The .NET Browser is a really handy online tool (at DotNet2TheMax) to browse your favorite .NET assemblies from the .NET Framework 1.1 and 2.0 Beta 1. It also shows changes to types from version 1.1 to 2.0b1. But what sets it apart from other online object browsers, such as Matthew Reynolds’ .NET 247, is that it (already) covers version 2.0b1 and also shows which members of types take or return certain types.
Link from Dino’s Esposito’s weblog. He mentions some other nifty features of the tool.