Old_Honky - 9:04 am on May 9, 2013 (gmt 0)
I would go for a stylised "IB" after the style of the guy from Krypton. With a suitable strapline which is always used e.g.
"Is it a bat? Is it a dirigible? No it's IncrediBill!"
"That's no masked man that's IncrediBill"
You are going to need a sidekick like Tonto or the Boy wonder, and I would go the whole hog and have at least one super pet, how about "IncrediGerbill".
Also you need some sort of geeky friend; either a photographer or a news reporter, who becomes "IncrediBill's friend" and provides you with useful information in return for you saving his/her life occasionally. The friend may or may not know your secret identity, but he/she will at least suspect they know your secret.