Laptops that Boot From External Drives?

ducman asks: "I'm a consultant and carry two laptops. I have to assume that my employer can see everything I do and access every file I store on the machine they provided me with. But I'm tired of hauling two laptops (and power supplies, etc) everywhere I go. My personal machine is an Apple TiBook, which will boot off an external, firewire drive. Could I do the same thing with an Intel laptop and run Linux on it for personal stuff? Am I the only one with this problem?" Which Intel-based laptop, that supports booting from an external drive, would you recommend?