BTW: sorry about the pictures, i don't have a steady hand :)
Step 1: What You'll Need
First up are the Legoes (maybe you'll need less or more based on the size (dimensions, not storage capacity) of your drive):
2 c1 1x4 flats
2 c1 6x4 flats
3 c2 1x4's
4 c2 1x4 flats
2 c2 2x2 flats
1 c2 2x4 flat
1 c2 1x2 flat (not pictured)
1 c3 1x4
2 c3 1x2's
And the other parts:
A USB drive
Something to open your drive with
Step 2: Opening Your USB Drive
Step 3: Put It Together
1) Put 3 c2 1x4's and 2 c2 1x1's on top of a c1 6x4 flat as pictured. Maybe you'll need to put other parts on it too or have a bigger base based on the size of your drive.
2) Put the drive in and press it firmly. Be sure you press it or otherwise the top part maybe won't fit!
3) Now put a c1 6x4 flat on top of the whole thing. It won't fit, but if you keep pressing it'll fit.
4) Flip it over and put a c2 1x2 flat on it. I didn´t have enough battery life to picture this, but it´s 1 row away from the end, in the middle.
OK, so now you have the stick, on to the thing that protects it (i don't know what's that called in English)
5) Put a c3 1x4 on top of a c2 2x4 flat.
6) Add a c2 1x4 flat and put 2 c3 1x2's on top of it.
7) Put 2 c2 2x2 flats and a c2 1x4 flat on top of the whole thing.
8) Flip it over and put 2 c1 1x4 flats and 2 c2 1x4 flats on it.