title: What should I use for a BigInt class in .NET?
body: <p>Until BCL finally ships <a href="http://blogs.msdn.com/bclteam/archive/2008/01/04/where-did-biginteger-go-melitta-andersen.aspx" rel="nofollow noreferrer">System.Numeric.BigInt</a>, what do you guys use for arbitrary precision integers?</p>