Best way to initiate RSACryptoServiceProvider from x509Certificate2?

Note: While this is the accepted answer and was valid back in 2011, this code won’t work now under .NET Core. See this answer if you are using .NET Framework 4.6+, or .NET Core / .NET.

RSACryptoServiceProvider publicKeyProvider = 
    (RSACryptoServiceProvider)certificate.PublicKey.Key;

and

RSACryptoServiceProvider privateKeyProvider = 
    (RSACryptoServiceProvider)certificate.PrivateKey;

The key property on the public or private key property of the certificate is of type AsymmetricAlgorithm.