I have Western Digital Firewire/USB2.0 and a Maxtor 5000DV Firewire/USB2.0 drives. Both are 160GB and 7200 RPM and I run them off of USB2.0 - they both work great for video editing. I have also captured directly to them through USB with absolutely no problems.
For a laptop you will need USB2.0/firewire and if your motherboard doesn't have it standard, there are PCMCIA cards available that have both firewire and usb2.0 ports on them for <$30.00