Well, I read that thread about Diablo 1 on the Ipod Touch, and it got me thinking how it would work. After thinking about it for a long time, this is how I thought is should/would look:
Click on image for a zoom.
Just did some work with Photoshop. Gave me something to do and was tons of fun! I wish Blizzard would port this to the Ipod Touch for real.:D
The Right Click button would be held down with your left thumb while your right thumb clicks on a monster, thus casting a spell instead of attacking. You would just click on the potions to use them, and hold down the right click button to move them/throw them out. There would be no Spells window, just choose your spell by clicking on it. The map would be accessible by the Menu button and the black box at the top would display item descriptions and whatnot.
diablo 2 i didnt knew... but my brother haves the d1 on his regular PSP... just search how to play ps1 games on the psp. the only anoying thing is that you cant run... just like in the pc version of the game.
edit: Btw, you should see a game called "Dungeon hunter" for the iphone. i dont have it but it looks just great