What makes the celeron slow is the cache size, which isn't a train smash if you just want a laptop to do things like web browsing, music, movies(you not gonna have the movie jutter etc) and so on. But if you wanna play games, use photoshop, video encode etc then avoid the celeron...
Honestly, a laptop should be used as a portable device where you do your work on, buy shyte for the web, do general stuff on it while away from the desktop... you shouldn't be aiming to video edit etc.
Edit,
How much do you have to spend on the laptop? I mean, we all could help you![]()
Apparently PS CS3 runs well on an Intel Atom 1.86 GHz (that's with HT enabled).