Bilbo

Bilbo Baggins was the main character of J.R.R. Tolkien's The Hobbit. He was a minor character in The Lord of the Rings. Bilbo was hired by Gandalf and Thorin to help Thorin and his band of Dwarves to reclaim the dwarves' treasure from the dragon Smaug. Along the way, he discovered the One Ring, which he thought was just an invisibility ring. In the Lord of the Rings, Bilbo left the Shire for Rivendell. Before he left, Gandalf discovered the true nature of the ring and persuaded him to leave it with Frodo. Bilbo lived out the rest of his life in Rivendell, where he wrote his memoir, which became The Hobbit. 

There is also an asteroid named 2991 Bilbo.

I like that you could use the nickname 'Bill', or 'Bo', and ends in 'O' names are very popular right now. Despite these attributes, Bilbo does not appear as a name in the Social Security Administration's name database. Unfortunately the name is too closely associated with the character to be usable as a first name for a child. It could be used as a quirky middle name, or as a name for a beloved pet.