Most modern subnotebooks don't really have speed issues for light to medium tasks such as internet browsing, MS Office, etc. I even use my Fujitsu for video capture via USB2. It works like a champ. I also use it to do audio editing. Again, it's not lightning fast but it works. You can forget gaming and such though. There's no 3D to speak of.

To minimize speed issues, there're three areas to watch, memory, processor and hard drive. Graphics is a fourth but ultraportables all stink in that area.

IMO, the main issue with apparent slowness is due to the hard drive. The other two aren't as much of a problem anymore. For the ultraportable Sony machines, the hard drive is a 1.8", 4200RPM drive (akin to what goes in the HDD Ipods). Mind you, it's not bad but it can't keep up with the 2.5" drive in the Fujitsus. Also, they aren't easily upgradeable at all. On my fujitsu, I replaced the 4200RPM drive with a 7200RPM drive. It gets a bit hotter, and perhaps took 10 minutes off the battery life but the speed increase is MASSIVE. That's the primary reason I stick to the Fujitsu line, the optical drives and hard drives are easily removed and swapped out for better.

As for the other two issues... You want a gig of memory. 512MB will work, but it's not quite enough for the most intensive tasks. This is only really an issue for those notebooks where 512 is the maximum. Processor speed isn't much of an issue anymore either. One caveat, AVOID the Transmeta Crusoe. It's slower than a dog. All that's out there otherwise now is the Pentium M ULV at 900-1.2Ghz depending on how old the model you buy is.