Always been a fan of TightVNC over other VNC variants because it's free, supports file transfers and is faster than other variants. Haven't been using it for a while since they haven't worked with windows 64 bit OS'es. Looks like since May (or earlier),
www.tightvnc.com/ has worked with 64 bit windows OS'es. I currently have it working with Win7 32 bit viewing an XP Pro client, next up is a Win7 64 box, will let you know how it goes.
Maybe I can say goodbye to RDP, with it's clunky connect/disconnect and problems with BOINC CUDA clients.
edit- working fine from a WIn7 32 to Win7 64 client. Will check XP to Win7 64 later