Great! Thanks, some of them are indeed very useful - George The Writer

No problem, if you have any suggestions be sure to send them my way! - Steve Spalding

Nice roundup. Still need to jump into Twine - Caleb Elston

Yea, if you haven't tried Twine yet you definitely should. - Steve Spalding

Does Twine still need an invite code? - Andy Murdoch

Yea, send me a message on Twitter or something and let me see if I can find one. - Steve Spalding

Kayak looks like a great find.... - Chris Reed

Excellent list Steve, great job on this one. - Svetlana Gladkova

Thanks Lana, I only hope people get some use out of it. - Steve Spalding

Kayak is great. My favorite site for price hunting. - Tsega Dinka

@Tsega I also like Sidestep a lot -- one of the two usually has the best deal. - Steve Spalding