I found two really cool programs. SharpMT and Pocket SharpMT. Both allow you to create entries offline, for posting to Movable Type based weblogs, like PHactotum Wheneverly. SharpMT runs on http://www.microsoft.com/windows/default.mspx with the .NET Framework and Pocket SharpMT runs on Pocket PCs with the Compact .NET framework. So far I am liking both products.
You can read more about it at The EpiCenter Blog