[plinkplonk]

Thoughtworks uses a (very simple) coding problem as the first step of the interview process. When I interviewed there, I found the problem too simple and was doubtful as to its value till I saw how it worked from the inside (after joining Thoughtworks).

Vast hordes of candidates with err "augmented" resumes get filtered out, as do "experienced" programmers (sometimes calling themselves "architects" and such) who haven't coded in (literally) years.

I would have thought more people would look up the solution online , but apparently even that effort is too much.

So, overall I would say a coding problem is an excellent idea. I am not sure how valid is the "tell me your program letter by letter over the phone" approach yahoo, google etc seem to take in their phone screens.