A few weeks ago i purchased a dual sim adapter for my S2
Its been a great little device for switching sims quickly. It didn't require cutting my SIM cards it was installed within a matter of minutes. Anyway i've been really impressed with it so thought i'd share it here. Here's a video of it in action...
Oh this is the item/ location i bought it from... http://www.magic-sim.com/product-details.php?Product=9