This week I've opened a Master Lock 'Titanium' range padlock. It's a 'mid-range' lock and costs about £15. It comes with a thick black plastic outer case, covering a titanium shell. The shackle is hardened steel as usual.
First I levered off the outer plastic casing with an old screwdriver, then, with the lock in a vice, ground down the four rivets on the back of the titanium shell with my Dremel tool. Once the rivets were flush with the shell it was just a case using a nail punch, then a steel rod to push the rivets all the way out. There was also a small weld, joining the two halves of the shell together, just under the keyway. I used the Dremel with a reinforced cutting blade to cut through the weld in about a minute. Not exactly 'non-destructive' lock opening, but very effective

Here's the lock with the plastic casing and rivets removed:
http://img.photobucket.com/albums/v609/gsmyth/002.jpg
The shackle does not 'pop' open on this model, it works on a geared mechanism. When the key is inserted and the plug is turned it engages a toothed gear wheel to move the shackle clear of the casing. Here's the lock with the titanium shell and inner backplate removed (viewed from the rear).
http://img.photobucket.com/albums/v609/gsmyth/003.jpg
You can see the gear teeth that turn engage and rotate the shackle clear of the casing. The lock itself is just a standard four pin tumbler:
As I said, this is one of my pratice locks and I've been having major difficulty picking it open. The problem I find is that the keyway is very small and once the tension wrench is inserted there's very little room left to manipulate the pick to raise the pins.