In the same way that you can escape WikiNames with a !, how about using it to generally escape structured text formatting characters?
! escapes structured text if it directly precedes a formatting character.
!! actually puts a ! if it does indeed need to preceed a formatting character.
On the Zope list, Jim said that he didn't like this suggestion. He suggested `` xxx '' instead.
SteveA pointed out that Jim's suggestion makes code like if s == '': return difficult, and suggested `` xxx `` instead. (FDrake agrees with SteveA on this.)