Google Apps with Sync. Chances are you already have a Google account of some sort. Well, Google does offer a syncing service for its contacts, calendar, and email services — all for free. And best of all, it supports push syncing in your iPhone, iPod touch, or iPad. Once you have your Google account set up with a Gmail address, a calendar, and some contacts, just follow the instructions found here and you’re all set.The end result: once you make some modifications via the web, the changes automatically get pushed to your mobile device and vice-versa. So now the built-in contacts, calendar, and mail apps in the iPhone OS are now fully synced to the web.

Flickr. iPhoto has built-in support to upload your photos to Yahoo’s Flickr service, which allows to upload a handful of albums for free. But if your collection is massive, a Pro account is definitely a great investment at $24.95 for one year of service.

Dropbox. This is one of my all-time favorite apps: Dropbox provides for free 2GB of storage on the web — which may be enough for most users — but offers more as part of their premium service. What sets Dropbox apart from iDisk is that it’s a lean, mean, syncing machine that works across Mac OS, Windows, Linux, and even mobile OS’s like the iPhone’s thanks to their free syncing software. In fact, in your computer, Dropbox behaves just like any other folder — you won’t even notice a performance loss as stuff is being synced.

Undercover. This app, available for $4.99 in the App Store, is a decent alternative to MobileMe’s Find my iPhone. Once lost, Undercover allows you to send your iPhone, iPod touch, or iPad a push notification to get the thief’s (or, hopefully, a good samaritan’s) attention and get him to open the app. And when it’s opened, Undercover may be disguised as a web browser displaying an address of your choice to allow it to capture its current location via GPS while the current holder of your device is distracted. Where it is lacking, compared to MobileMe’s Find my iPhone, is that it doesn’t allow to remotely set the lock screen or wipe the device. At the end of the day, though, unless you’re carrying sensitive information, Undercover is better than nothing — and only costs five bucks (that are even backed up with a money-back guarantee).

Google Chrome, with bookmark syncing. The newest version of Google’s Chrome web browser has built-in bookmark syncing through your Google account, which is perfect if you end up using other computers with Chrome installed — but not so much if they don’t. The great thing is that it’s extremely easy to set up if you already have a Google account: just go to Chrome’s preferences, and look for bookmark syncing under the “personal stuff” tab. Of course, my only exception is when I intend to do some browsing in my iPad.

Bonus app: Instapaper. But I don’t let the lack of non-Apple bookmark syncing in my iPad bother me. In fact, I’m doing good thanks to Instapaper. If I find something interesting while browsing at home, I just save it on Instapaper and have the Instapaper app in my iPad sync all the new additions. Now I can read my stuff on the go, with the benefit of it looking more like a book than a browser window.

Updated 5/25/10 to edit some word choices to avoid confusion on this post’s purpose.

Mailplane. I recently made the switch from Apple’s Mail app to Mailplane because of the convenience of having the power of Gmail right within my desktop. Simply to be told, Google’s powerful search engine allows me to glide through the thousand of emails that plague my inboxes. Not to mention that Gmail will grant me access to my mail from anywhere in the world where I can find a decent internet connection.

Twitterrific. Twitter’s popularity has grown tremendously, up to the point where you actually want to know what is currently going on to the people close to you — or complete strangers. Hence, the concept of mini-blogging has become quite a phenomenon. Twitterrific is the best app that integrates Twitter in your desktop.

Pukka. The ultimate Mac app for working with the ultimate social bookmarking website — del.icio.us. With neat features that allow for adding quick links, to and from your account, make this one a gem.

TubeTV. If you’re bound to lose hours and hours with YouTube of what could’ve been used for productivity, then this app will at the very least allow for more hours to be lost on-the-go thanks to the iPod conversion settings.

PackRat. To sum it up in a few words, it integrates 37signals’ Backpack to your desktop. If you rely on the web app more than you’d like to, this one is a time-saver.

FlickrExport for iPhoto. Now that your iPhoto library is full with fantastic pictures, it’s time to share them with the world — and maybe .Mac isn’t for you. So with this fantastic plugin for iPhoto, it’s insanely easy to import the pictures to a Flickr account.

Evernote. An innovative online service for keeping track of all your notes, and syncing them across any desktop clients you may have installed in various computers. The most interesting feature is its capability to search for text within any photos that have been uploaded to your account.

Fluid. What seems to be the mother of all web apps — if there’s no desktop client of a web service you currently use, Fluid is leading the pack to bring every single web app to your desktop. It’s definitely better than using your web browser.

These are some of the most popular apps that bring the life of the web to your desktop. If you have a favorite one that wasn’t mentioned — after all, there are a lot — feel free to share it in the comments.

Watched the video? Okay… wow. Where to start…? Well, as seen, the Delicious team is really going for customer satisfaction by adding some very requested features, and more yet to see.

The ability to publish your library online was the biggest request, and now it’s finally been added. No longer will your huge and drool-worthy library be confined within your Mac — now the whole web will be able to feel envy for your collection. And a gadgets section will be able to show off your most interesting toys, too.

But what is the most interesting addition? That’d be iTunes integration with a media launcher. Yes, Delicious Library now also is a Front Row rival with more eye-candy than the original. Just imagine a Mac media center with Delicious Library working as the main menu…

Also, stay tuned after the Delicious Library stuff is done to see Mike talk about his work with charity (Thievey.org). Interesting stuff, indeed.