Jesper Joergensen posted some interesting info last week about a new endpoint for the API that is currently available. The new endpoint is https://login.salesforce.com and according to Jesper will reduce your authentication time slightly.

While you’re at it, you may want to update your SOQL queries to take advantage of some of the new Aggregate Functions.

Check out the full post at http://blog.sforce.com/sforce/2010/02/new-api-login-endpoint.html