Twidroid
It seems like every platform has a half-dozen Twitter clients these days, but on Android, Twidroid from Ralph Zimmerman and Thomas Marban is the reigning king.
In addition to the usual ability to send tweets, view replies and direct messages, and follow or unfollow people, Twidroid integrates with Android's browser so you can tweet links to pages you find interesting; captures GPS information to tweet your location or to geotag tweeted photos; and offers a selection of URL shortening and photo hosting services.
It's all wrapped up in a clean and stylish interface that's easy and fun to use.
Video Player
The creatively named Video Player app from Android Tapp does exactly what it says: It plays videos, a function that Google mysteriously chose to leave out of Android.
Video Player isn't fancy; you can play, pause, move backward and forward through the video, and that's it. It plays only H.264 and MPEG-4 videos, and only from an SD card. But it is the only free video player available for Android right now, and it works well despite the meager feature set.
Conclusion
Google is well known for releasing products with few features and then adding new ones later, apparently at random -- which means we can assume that several of these apps will either be acquired by Google and integrated into future versions of Android, or will be superseded by Google's own updates.
For the immediate future, though, the Android Market is your ticket to a full-featured smartphone that gives you no reason at all to feel ashamed in the company of snarky iPhone-bearing friends and colleagues -- and, in many cases, reason enough to feel a little bit superior yourself (well, let's not push it).
Got your own Android app to recommend? Let us know in the article comments.