I came across IconBuffet when registering my copy of Visual Studio Express. They have some awesome icons that you could use in your applications.
For application development I have also started playing with WPF interfaces in .Net, soon to be available on Mono as well. With the ability to use web images and pictures in Windows Applications even not creatives can develop some awesome interfaces.
For website layouts I use sites like OSWD for designs and layouts that are free.
