[whpalmer4]

What Lizard said seems not to contravene any GTD concepts of which I'm aware.

Another variation might be to capture to OmniFocus, but when you process your Inbox, actually store the idea elsewhere until you're ready to turn it into an active project. Slightly more effort, perhaps, but offset by increased flexibility in the other tool? Again, I think this is totally in keeping with the GTD philosophy of capturing everything in the Inbox, then fanning it out to reference files, action lists, someday/maybe, delegation, or trash.