BrainBench, an online testing website, offers its exams for free till July 14th. Personally I would give more credit to the Microsoft certification, since these are taken in an exam center. But if you want to get some free BrainBench exam certifications, now might be the time to give it at try. They do have some tests about the .NET Framework...

PS. Currently I don't see anything about this on their homepage, but on this page you can see the following statement: "July 1 - July 14 we are opening up the Brainbench library in celebration of our 5 millionth member. All tests will be FREE.".