Okay, I'm feeling left out over on the iPhone Apps thread, so here's one for us cool kids.

• RealCalc: An HP10 (albeit portrait mode) feelalike calculator.
• Arity: a 2D and 3D graphing calculator
• ShopSavvy: Scan product (UPC, mostly) barcodes with your camera, look up product, and find prices online and in nearby stores
• Barcode Scanner: ShopSavvy is nice, but it only supports a few types of barcodes. Barcode Scanner can read everything I've thrown at it so far, except non-QR 2D bar codes. It also provides a barcode scanner and generator library for other applications.
• deciBel: an SPL meter. You have to calibrate it, since it doesn't know the response of the mikes in different devices, but it's pretty neat to have a somewhat accurate SPL meter in your pocket
• RTA Audio Analyzer: an audio frequency analyzer
• DinoDyno!: accelerometer-based auto performance analyzer. Worst possible app icon
• Bubble: turns your phone into a bubble level. Graphics show actual bubble, making it intuitive, plus shows angle in degrees and contractor-style rise-over-run. Works on all four edges, plus the back, where it shows a bullseye spirit level.
• Google Sky Map: a star map. You say "so what". I say "point it at the star you want to identify and it shows you the map where it's pointing. I don't really have a lot of use for this, but it's super-neat.
• Shazam: Neatest application for any portable device. Tells you what song is being played.
• IRC Radio: an IRC app that's reasonably good on its own, but ups the ante by optionally piping the content through text-to-speech.
• ConnectBot: the obligatory SSH app. Also does telnet and provides an interface to the local shell. (Telnet doesn't work for raw connections, sadly, so no telnetting to port 25 to test SMTP.) Supports public key authentication and has a good interface for Ctrl characters and Esc.
• gStrings: chromatic tuner, as for tuning a musical instrument
• Sudoku Camera: take a picture of a printed Sudoku puzzle and have it import it into a Sudoku application. You generally have to make manual corrections, but it makes that pretty easy, by showing you the picture underneath the generated numbers. Trial only, but for Sudoku addicts, pretty darned neat.
  And since we're talking Sudoku, here are the apps that Sudoku camera will work with:
  • Andoku: Nice attractive sudoku (and sudoku extensions) app, but has no support for notes.
  • OpenSudoku: Only plain-flavored Sudoku, and a marginal UI, but support notes.
• Crosswords: Good crossword UI, supports .puz files, but no built-in downloader (or built-in puzzles, for that matter).
• Abduction!: Save your animal brethren from the space aliens by bouncing up platforms. Super-simple, super-fun vertical platformer, controlled by tilting.
• Radiant Lite: a Xevious-like arcade game with neat retro graphics. Just a demo, but a very long demo.
• Robo Defense: decent tower defense game
• DailyStrip: viewer for online comics, including xkcd. SHould support notifications, but doesn't.
• What the Doodle?: online Pictionary. Fun until you get retards drawing genitals or just writing the phrase they're supposed to draw. There is cheater voting, but some people seem to think that it's okay. It's probably better when amongst people who paid.
• App Referer: show QD codes for apps on your system so that another person can scan them to download the app quickly. Relies on Barcode Reader.
• Calorie Counter: interface to FatSecret.com. Keep track of your daily food intake. Uses FatSecret's food database, plus lets you scan the barcodes of packaged foods. I'm sure there are others just as good; this is just the one I stumbled across.
• CIDR Calculator: for network admins with bad memories, like me. Calculates netmask info.
• DealDroid: checks woot and woot-like web sites and notifies you of current deals.
• PackRat: media database. Scan the barcodes of your CDs, DVDs, video games, books, etc. and import them into the database
• Alice: notifications of your favorite music acts playing in your area.
• Astrid: task manager. Syncs with Remember the Milk
• Ultrachron Lite: nice stopwatch/timer app that will read out a countdown and other times.
• Weatherbug: weather forecasts. keeps the temp and other basic weather info in the notification area. Will track your location. Includes widgets. (By the way, other than the data itself, the The Weather Channel app sucks.)

and last, but certainly not least:

• David Lee Roth Soundboard: I can't improve on this Market comment: "The greatest application ever made. I suggest using one of these as your notification sound. It will change your life."