Well - more gadgets. I got GBA SP just a week ago. Now I don't need to waste my time for reading a good book on my way to work since I can just play stupid video games! So far I've tried Puzzle Fighter II (an excellent choise for people who like Tetris and Tetris Attack (TA has nothing to do w Tetris, but the name was changed for US markets), Metroid Fusion (interesting platformer, action adventure but maybe a bit too hard for my skills), Super Mario Advance (This game contains actually two games - the original Super Mario and Super Mario Bros. 2. SMB2 is a tuned version that has a lots of minor upgrades and new fancy stuff incl one new end level boss. For SMB2 fans this is a must have!). The last one is Golden Sun - a traditional JRPG, which is a very good and enjoyable adventure with decent puzzles.
Sorry - I'm lazy so I just stole the picture.