If you want to play some Lumines on your PSP (if you have one), but can't be bothered with carrying round the UMD, and would like it to only take up a small amount of space on your memory stick... and you're not bothered about unlockables... You can download the demo version here.
I got the heads-up on this from Siliconera and it has more on installation instructions there (if you can't read Japanese).
