Below are a few pictures of a useful (homemade) hamstring apparatus.  The images and video are courtesy of Dane Miller at Garage Strength (who has been fortunate to train alongside Dr. Anatoli Bondarchuk).

Full instructions and a related blog entry for this device can be found at the link below:

Hamstring Pulls: Building The Equipment

Per Garage Strength:

Materials: long decking screws, 2 8′ 2×4s, sheet of plywood, thicker piece of wood for plank for feet (or use leftover plywood)

1. Cut a piece of plywood at a length of 4′ (this is factory width) and then cut the desired width…we used 31 in.

2. Cut an 8′ 2×4 in half so u have 2 4′ pieces.

3. Screw the 4′ 2×4 along the 4′ sides of the plywood. Make sure that the 2×4 is upright… screwed on the 2″ side.

4. Place the piece of wood used by your feet at the desired angle and then screw it into the upright 2×4s

5. Cut a piece of 2×4 to screw to the upright part of the angled plank for stability and strength.

6. Repeat on the other side

7. Finished!

You can also see a video demonstration: