Here's a quick post for those of you following the GP2X Caanoo. One commenter asked about the battery life, so I came up with a "real world" test to gauge the battery life. Note that I did not change the system's clock rate which would impact the battery life, but that could go either way. For some things, you could clock it down to save life, and for other things (like emulating certain systems), you may clock it up to increase performance.
My "real world" test consisted of me watching a movie and then playing some emulated games on the GPH Caanoo. This was a bit simulated, though, because I didn't actually watch the movie or play the games. The movie just played while I did some other things. The games I chose were all emulated arcade games. I chose them, because arcade games have demo modes that sit there and show off the gameplay until someone inserts a quarter. That way my tests were always stressing the CPU even though I wasn't actually hitting buttons.
At time zero, I started "Howl's Moving Castle." You can see, from the screenshots, that the battery was full when the movie started. Then, at the end of the movie (1-hour and 56 minutes in), I took another screenshot showing that the battery indicator still shows full battery. Oh, and I set the movie player to half brightness. It looked fine at that setting, and I figured it was a good average.
After 2 hours of movie playing, I shut the machine down, so I could switch SD cards (to the one with the games). I booted the Caanoo back up and started MAME running Shock Troopers 2nd Squad (and the clock set to 533MHz). I let Shock Troopers run for 22 minutes. After that, the battery was down to 2/3 full.
I switched to Out Run, and let that play all through my commute and dinner. It was almost 2 hours of Out Run, and by the time I was finished eating, the battery was at about 1/3.
I ran Tetris for about a half hour, and then I switched to Cadillacs and Dinosaurs. 12 minutes into Cadillacs and Dinosaurs, I found the machine dead.
The final conclusion is that I got 5 hours of real-world playtime out of the Caanoo's battery. I think that's pretty nice, because I was doing some intensive stuff. I'm sure that if you were just listening to MP3s or reading e-books, you'd get way more time out of it. Perhaps you could even double it, especially if you clocked it down.