Best nicknames or alternatives to Wil...

You could always use my BIL's name, Wilhelmus. Ha ha! He was born in Holland.

I like Liam too, though it's been done a lot lately. How about just calling a little boy William? I only know one "full-time" William; he's at my daughter's daycare. I think he's 7 and he's serious but a total sweetheart. The name seems to fit him perfectly.

Oh, I think Prince William's family calls him "Wills." Just remembered that. :)

And Bilius? You're not serious, right? It's just an O away from:

bil·ious/ˈbilyəs/Adjective
1. Affected by or associated with nausea or vomiting.
2. (of a color) Lurid or sickly.