Convert.ToString() only allows base values of 2, 8, 10, and 16 for some odd reason; is there some obscure way of providing any base between 2 and 16?
You could try the following:
http://www.dotnetspider.com/resources/938-Conversion-Decimal-number-any-Base-vice.aspx
This at least gives the impression that you could have any base (from 2->16). Although Im a little confused as to why you would want to !