To find a personal N-number http://162.58.35.241/acdatabase/acmain.htm

RV builder Gary VanRemortal's Builder's Yeller Pages  http://www.sound.net/~hartmann/yelrpage.htm

Get your US Customs sticker http://www.customs.ustreas.gov/travel/travel

Calculate true air speed by flying 3 GPS legs  http://www.ntps.com/GPS_SpeedTrack.XLS

A density altitude calculator http://www.pilotfriend.com/density%20altitude%20calc.htm