We've shared a lots of different ways to manage the cables under your desk, but Instructables user getgreg offers a simple solution that gives you super easy access to your power strip. All you need is a wire basket.
This method isn't all that different from something like the rain gutter solution, but it has one simple addition: with a large enough wire basket, you can actually fit the plugs in your surge protector through the holes. That way, if you ever need to plug something in or take it out, you don't have to go swimming in a sea of tangled cables — you can just reach up, unplug it and throw something else inside.
On its own, it doesn't fit a ton of cables, but coupled with something like this binder clip method or a few Cablox cubes, you could probably have a pretty clean system going on under your desk.. Hit the link to see how he put it together.
How to Mount a Power Strip (and Power Bricks) Under Your Desk [Instructables]