Sup - which editing software are you using for these tennis vids. i'd love to see PP's serve broken down in slow motion. i betcha you could probably coax another 5-10mph with tweaks.
oh also before you buy the HD camcorder - cnet.com did a roundup of pocket sized HD camcorders. these suckers are usually less than $200 and take good but not great video. but they're easily portable and double as cameras too. then they did a roundup of less than $600 HD camcorders. i've used most of the JVC and Canon lineups for HD camcorders including the hard drive and mini-DV versions. i'd go with the Canons. they shoot better video. plain and simple. go with JVC if you need more storage - they got one that has 120gb drive. prolly overkill.