I'm looking for a device next to my N900, and came across the OpenPandora, is it faster than the N900, and can it do anything more than the N900? Or should I ditch this plan and get a real UMPC instead?

There are a few versions of the Pandora, and they vary in price and performance. The 1GHz version is likely somewhat faster than an N900. It's also got twice the RAM of the N900, which could reduce swapping a fair bit if you're using a lot of memory.

What are you looking to do? You could try looking around the main repository to see if there're any applications there that interest you.

Probably worth noting here that both the N900 and the Pandora have successor devices in the works: Neo900 to the N900, Pyra to the Pandora.

Should've checked the hardware specifications m8.
The Pandora runs a Cortex-A8 at 1GHz, which is almost exactly the same processor the N900 uses.
It's faster in the sense that browsing the web with more than 2 windows open doesn't lock up the entire device, but it's not worth the €500.

Wait for the Pyra
http://www.pyra-handheld.com/

Edit: "Fixed typo from checker to checked."

That's a very important kind of 'faster'

but yeah, I'd wait for the Pyra too.

EDIT: for the record, the 1GHz Edition actually uses the same SoC as the Neo900, not the N900.

I have both the N900 and a 1ghz Pandora. I still use both and take them on trips in lieu of a laptop.

I think that the Pandora is serviceable as a short-term laptop replacement (i.e., reasonable to use when traveling). It's great at running emulated games and the 1ghz version runs LibreOffice passably well, if you need a productivity suite.

The big weaknesses of the Pandora for me is the poor wi-fi performance. It's so bad that it is recommended that you purchase an external USB wi-fi adapter. Even then, the web-browsing experience (surprisingly) can be painful--certainly it is not as good for me as it is on the N900. Also, build quality could be better.

Again, that's my take on it. I am hopeful that the Pyra will address some of the issues that have plagued the OpenPandora (which is, for what it is, still a unique and fun device to use).

Web browsing and gaming, and using Rockbox of course!

EDIT: After reading some reviews, and they said that the build quality is bad, I'm going with either a Panasonic Toughbook CF-U1 or CF-19, as I can do a LOT more with those than a Pandora, and I can throw the U1 in my cycling backpack without harm, but I'll keep it open as an option though.

(ALMOST) One year later:

Forgot about the OpenPandora, but one day in September I was at a computer parts guy, and he had a Toughbook CF-18 Mk2 which I could have for 20 euros!

Fast forward to December: I imported a CF-19 Mk2 from the US to NL, and then sold it with profit after I found a CF-19 Mk5 for VERY cheap, which I am still using as of today. (hell, i'm even typing this message on it!)

A few months later I finally got a CF-U1!

Shame I can't play Youtube on it because of the worthless GMA 500 GPU support.