is there a big difference between the sony psp slim and the psp 1001?

First off, hardware specs. Sony added a bit more ram to the slim ( i dont know the details, yull have to find them out) and they decreased battery size by 1/3. Note that the psp FAT battery that is the psp 1000 can fit into a slim but the cover wont go on.

The PSP 1000 (FAT) is much easier to hack then the psp slim so you can play homebrew applications on it. It is possible with the slim but its a whole lot harder.

Color (:D) the psp 2000 (slim) has more colour options then the 1000

There are extra official (sony) apps for the psp 2000 suck as skype where you can talk with people

Thats about all i can think of right now.

Bottom line is the psp slim IS worth the extra hundred as sony might come out with more apps in the future and it has exclusives now. The battery charge is lower but you can use the 1000 battery and buy a special cover to fit over your new, shiny, better, psp 2000

You can run more unofficial software on the 1000 but most of it is possible on the 2000

Personally id go for the slim but it's up to you

First, the psp 1001 is older and fat. A program called Skype is coming for psp, where you can make phone calls from your psp for free. This is only available with the slim edition. Try Craigslist to find deals for PSPs.

A God of War psp slim edition is coming out soon, just like the star wars. It's going to be a red psp color with the God of War game and Superbad movie. If you like all that, it might be worth waiting on.

Actualy, there the same, some call the redesign slim and some will call it slim. Between the first and second model the main difference is the newer one don't have the spring loaded UMD holder and there's a video output that can let you play your game on a TV.