For what it's worth, I think you need to developer unlock the phone to do this.
I wanted to do this myself, but then I realized all the WP browsers are based on IE, so they don't really do anything to help render webpages differently and IE still seems to be the fastest.
I tried SurfCube for a while, but got tired of watching the load screen every time I launched it and just went back to IE.
I think when we've actually got some options that AREN'T based on IE, like maybe Opera? or Chrome, then this will be a much more relevant question to me personally. By then hopefully Microsoft will step out of the way and allow us an easy way to do it.