And by little, I mean little. No tablet ports, from the recent era of tablet computers. I like sometimes to kill waiting time with little games on my tiny smartphone (an xperia mini pro, these things have small screens), but I'm not good at finding decent freewares. Been playing mostly :

1) "100 doors" puzzles. It's a series of puzzles, fun but limited as the genre is.

2) Chess. This is what I play mostly (not at huge levels of difficulty, because I'm not great plus not terribly focused when playing on a mobile phone screen).

3) "Gurk", a cute free tiny ultima-like, with zero replay value. The sequel isn't free, and I like its enhanced graphics less.

4) Some dumb "Jaws" one-button kind of game. Amusing, but, well, okay, done.

Do you people play some elaborate freewares on your mobile phones ? Actual RPGs, turn-based strategy, or whatever ? After all, these devices can run a lot of things. I regret not having installed winuae and my amiga images on it before leaving, but looks like the whole amiga library would have run on it. So, there has to be some stuff. No ?

Vlak (Train) - android remake of old DOS logic game. Not sure how it is on small screens

If you want to play a RPG, check Pixel Dungeon. It's from one guy, he is still updating it, and it's free (by updating I don't mean its not playable - it's just that he's adding more content all the time).

It's a roguelike dungeoncrawl, with permadeath and randomness to meet everyone's desires. You just basically pick a class (warrior- considered normal mode; rogue - considered hard mode; wizard - unique play, don't pick him first) and go right in.

Basically expect lots of dying until you manage to reach the (so far) last level boss. I find it pretty fun and exciting. Has very high replayability.
I can tell you more about it if you ever decide on playing it. xD
I think I've spent good 15-20 hours playing it (it was pretty harder in the beginning) in the past 6-7 months.

EDIT: That's basically as elaborate as it gets on Android, whilst still being free. I've spent quite some time searching for a good RPG to kill boring college classes. Besides Pixel Dungeon, I've played mostly tower defense-like games.
Thats one of the reasons my roomate and I decided to give it a try and develop a decent, non-crappy RPG worth playing for android, this summer. xD

It doesn't work on a phone. Believe me, I've tried it on two different devices. It needs a device of a minimum resolution that most phones won't satisfy.

By the way, the current Humble Bundle has some decent Android games.

The Amazon appstore has a daily free Android app of the day. Not sure if region restricted like their digital downloads are but you can check it out. It varies between games, productivity, amusement, etc. Today it looks like a racing game thats getting mixed reviews so I passed on it.
Sorry don't have a link handy from work since we have Amazon blocked.

Plague Inc

At first I thought you were referring to me.

Yeah, tried it, its awesome aswell!

at the moment I can think of Jetpack Joyride or Cut the Rope (the free version contains tons of levels)... Plague Inc. is also very good game

but the best games are (obviously) paid - for me at the moment it's Beyond Ynth, 9th Dawn or Plants vs. Zombies

there's should be a demo for all these if you're not certain...

and then there are all those strip pokers of course :)

I really enjoyed Andor's Trail long time ago, a very nice rpg game. Played it on a tablet, but should also work on a smartphone.

Hehe, with your name you could not dislike it :)

Shoot the Apple

It has in app purchases, but you can finish all levels with 3 stars without paying anything and it has around 400. It's a physics based puzzle game. It also has a second part, but I think the first one is better.

I liked Doodle Jump.

I'd also recommend NES (or SNES) emulator, especially if you used to play those games as a kid :P

chippers challenge (its a remake of chips challenge - not sure how this will run on a small screen)
Dark Galaxy (used to be called novawarsgame)
Wimp
fling
quote unquote (again that might not have been free now)
Robinson (im ashamedly addicted to this) - too small screen
SG:Deadzone - too small screen
ShadowGun - too small screen
solitaire
Star Trek Text Game
Tiny Village (ashamedly addicted too) - too small screen
Teeter
Trap
Water (as in wheres my water) - not sure about screen size
angry birds - too small screen?
cut the rope - too small?
from cheese (i think its free - im struggling to remember what i paid for on my devices)
GunBros (before it got pulled and made into multiplayer but its still good) - too small??

its a little off the wall but if you have the internal storage space - amazon apps ive got some great games off of them for free. some ive purchased in the past or the next version (i.e. game 2). but its always an idea? but just remember it needs amazons app store installed to launch and run so as i say you need the space on your Droid.

a word on the nes/snes etc emulator, get the original one, its free and runs fine. many in/on the marked are clones of the original emulator and they charge for it, the original one is free! (ill try find the name if your interested)

e: just read what you meant by little.

Deadly Dungeons
http://deadlydungeons.com/

EDIT: Ouch... sorry, it is no longer free. Well, it WAS free last year.