I stumbled into Fluid when I was looking for a way to keep my RememberTheMilk task list open on the side somewhere rather than always having a Firefox tab devoted to it (and trying to remember not to just close the Firefox window).  With Fluid, not only do I have an app dedicated to my RTM task list (and, since installing Gears into Safari^* makes it available to Fluid SSBs, it should have some ability to function offline, too), but I was able to create a separate menu-extra type app with the gadget interface to RTM so I can also access my task list quickly in the menu bar.

Having done that, it was a short skip over to having a proper Google Calendar app.  Nothing special there yet, save for the same hope that Gears will make it work offline.

More usefully, I found this post about using Fluid and Hahlo along with some scripting to create a pretty good Twitter client that even uses Growl notifications.  That post has all the links you need, including a direct link for the script and a link to a usable icon on Flickr.

Better still, it occurred to me tonight to apply Fluid to Lala.  With Fluid’s option to hide the window when the user closes it, rather than actually closing it, I can “close” the window that has Lala and it keeps playing.  If I go back to my Lala SSB app, the window pops right back up.

Mind you, while all this web-app-turned-mac-app stuff is nice, the biggest benefit is probably the fact that if my web-browsing browser crashes, it doesn’t take my web apps with it and no one of my web apps can crash the others.  Unfortunately, Webkit seems to share one big cookie jar among all its instances, so separate Fluid-created instances won’t allow you to simultaneously log into the same site using different credentials if you couldn’t already do so (the login cookies will clobber each other and/or any such Safari cookies… though Firefox’s cookie jar is separate from Webkit’s…).

^*note that, interestingly, the Gears site displays an essentially blank page with no help or guidance whatsoever if you have javascript turned off in Safari (I mast have been testing something or other without javascript and forgotten to turn it back on).