I think WinSpy++ looks like the best bet, especially since it ships with source and is compatible with Vista (Win7 too presumably).
However, the first clone I'd run across was WinID. No source and claims not to support Vista, but it may do some things WinSpy++ doesn't...like extracting icons and fonts ("Capture Shot").
Note: tried to post this as a comment and not an answer, but the link wouldn't work.