The "Snack Overflow" blog (from tech.graze.com) has a recent post sharing some suggestions to help unit test static calls without having to "refactor the world" away from them.
Imagine you have a situation [using a static method call] in some legacy code. Currently we can't unit test this as we can't mock out the doSomethingElse() call. So what do we do? Well we have two options really [...] neither of which is very appealing. [...] There is, however, a third option that gains us the ability to unit test Foo without having to touch Bar at all.
This option involves creating a "proxy" object of the "Bar" class that's non-static and only returns the result of the previous class' static method. You can then correctly mock that class and return the result in a more self-contained way. He lists a few caveats with this method including the fact that it could lead to a lot of proxy objects if there are a lot of static methods to replicate.