UK Webmasters... Whats A Cheap UK Travel Site?

My sister wants to come over for a visit in September for a week and im trying to find airfare prices from either Gatwick (nearest airport to Guilford) or Heathrow to Orlando or Sanford.

Any of you folks in the UK reccomend a good cheap travel site she can use to book her airfare on?

Regards,

Lee

Last Minute - www.lastminute.com

kayak.com or cheaptickets.com
kayak will open several windows from your browser, so it is not for the memory-impaired computer

travelocity.com is always worth checking -- and use the part "my dates are flexible" to find the better fares.