If you're wanting a fast solution that isn't smothering the turf then I agree with Alex - cutting off the turf would be the obvious way to go. The sod can be stacked somewhere where it will rot down in a year or so into nice loam for potting compost or top soil.
Sometimes it's better to go a slow route though if you can. By adding organic matter to mulch the turf (wood chips, straw, compost) to a good depth, you will increase the microbial activity and make the area much more fertile for growing plants (see
Dr Redhawk's soil threads for some deep reading!) I've got an area of turf where I want to start growing food, and am going both routes. One area I'm making into a lazy bed to sow into next spring, and the rest I'm trying various different methods all of which are designed to increase the organic matter and hence microbial activity in the soil.
What soil type and region are you? What do you hope to grow here and when?