Twitter? Gmail? The whole gang? On my desktop? Yes, as you’re reading this, more and more apps that depend on a web app or service are already infiltrating your Mac’s desktop. Here are some examples.

Tweetie. The current best Twitter app for your iPhone has finally arrived on the Mac. The final result has brought in some mixed feelings from the crowd, but most of them seem to agree that it is already one step ahead of the competition (at least the competition that isn’t in beta!). While most of the interface seems to be custom-designed, it is implemented very well. Hands down, Tweetie really deserves that spot on the desktop.
Fluid. This is the Swiss Army knife of bringing the web to the desktop. What this fantastic piece of software does is take your selected web site containing your favorite app/service and transport it outside of the browser and into the desktop. Having such web app bounce around in the dock is not fun? Then try a menu bar app, which Fluid also supports. Instead of bringing that web app into the dock, Fluid will send it into the menu bar; when clicked, the menu bar will pop out an attached window with the web app inside it.
Mailplane. This one is definitely one of my all-time favorite apps. To put it simply, Mailplane is an email client built around Gmail. It has all the features Gmail offers (which are a lot!), adds some Mac OS functionality such as media browsing, support for multiple accounts, and you’ve got a winner! Ever since I got this app around two years ago, I’ve transferred all my email accounts to Google, abandoned Apple’s Mail, and haven’t looked back.
EventBox. Kind of like another Swiss Army knife app for the Mac featuring some of the most popular services into a single window: Twitter, FaceBook, Flickr, Reddit, Google Reader and general RSS. And while it’s still in beta, their website already offers a brief glimpse of what is to become of this app: they’re building in support for del.icio.us, Last.fm, Orkut, and promise more surprises.
And the rest? Chances are you already have your favorite installed on your Mac. But if not, here are some more apps to use with del.icio.us, Flickr, Backpack, Evernote, Campfire, and a quick search on MacUpdate can reveal more.