Unless they've improved it lately, no, it's not. The spell-check features in OmniWeb are. Spell-check-as-you-type is definitely the way to go.

Agreed. I just wish I had my Mac laptop now so that I could run OmniWeb anywhere.

And unless I'm mistaken, the type as you go spell checking is actually part of the OS, and can easially be added to any application. I really hope Chimera adds it soon if this is indeed the case.