I gave a quick talk at Boston.rb this month about VCR, a tool that can help make your integration tests more deterministic.
I've been enjoying the tool quite a bit. It makes it really easy to interact with web services in your tests in a way that doesn't depend on the endpoint always being up. This approach leads to better, quicker, and more predictable tests. If you're already using WebMock or FakeWeb, this tool will automate the process of pre-fetching your response/expected result for you.
Hope you find them useful!