Mrs Northants JP and I are thinking of taking a holiday next year in the states West Coast. We were thinking of flying into LAX driving up the coast via SFO across yosemite and then to Las Vegas. We'd like to use my stash of 150K mikes. What's the consensus on the best use of miles.

(1) LHR-LAX & LAX-LHR or LHR-LAX & LAS-LGW

(2) Economy one way + UC one way or PE both ways (does it depend om route and direction)

(3) What about using them on another airline (Continental?)

(4) Any other combinations that may be worthwhile - don't really want to spend a load of cash so using miles on an upgradeable ticket isn't really for us.

thanks for any help