I bought an Android 2 & upgraded my plan less than a month ago. It's my first smart phone & I'm discovering I'll probably never want to go back. As for apps, here are some I've recently found on the market & used. They're not so much communication or organizational, but all either useful or fun, as well as free.
Barcode Scanner - Scan barcodes on products then look up prices and reviews. Scans both standard UPCs & those complex digital squares patterns.
Bit - It's the Bit from Tron, now available in a pocket size.
Bubble - Uses your phone's accelerometer to turn your phone into a carpenter's level. Very accurate.
Dismount - A fun & addictive rag-doll simulator game. Good for passing the time, relieving stress or for folks who just like pushing people down stairs.
Google Sky Map - Uses the magic of Google to show you exactly what's in the sky overhead as you look up into your phone, in real-time.
gStrings Chromatic tuner for any instrument. I use it with my theremin.
Pandora Internet Radio - Personalized radio service. Streams any music you want to listen to.
Pinball Deluxe - I'm very picky about video pinball games. This one isn't perfect, but it's the best I've found to date for Droid.
Shazam - Realtime song identification program. My girlfriend uses this constantly to learn more about new music she likes as it comes up on the radio.
Tiny Flashlight + LED - One of the best flashlight applications. Has the potential to drain the battery fast but can be useful in an emergency.
TweetDeck - The highest recommended (to me anyway) Twitter app. Much easier to use than the mobile website.
