Mobile software developers has released FlickR upload utility for Windows Mobile powered Smartphones under the name zipPhoto. With this utility you can take photos with your MS Smartphone device and upload them directly from your smartphone to your FlickR photo archiving service.
Note that this application only works for users who use the old method of logging in to Flickr and was built for Windows Mobile 5 phones, but should run on older smartphones too if you have installed .NET CF V2.