If you travel often, and you don't like leaving your reptiles or amphibians at home alone, and you take them somewhere to be watched, then I am sure you know that carrying a terrarium sucks. To make a handle for your terrarium/aquarium you need two things:
1) Terrarium/Aquarium
2) PC Case carrying strap

There are a few things to note
1) Do not attempt to carry a aquarium full of water with this method.
2) I am unsure, but I believe the straps will only fit a standard 5 gallon or 10 gallon x-long aquarium.

The reason I say this is, the glass on the side of the aquarium/terrarium was not designed to hold a lot of pressure the way it would be applied by the strap. If the aquarium is full of water chances are the glass will break under the weight (assuming you can lift it). Also, If you attempt to try this on a tall aquarium, the glass is also more likely to break.

(Forgive the crappy photos, I took them with my cellphone)

Step 1: Layout Straps

Layout the strap so you can set the aquarium/terrarium onto the straps.

Step 2: Place Aquarium/Terrarium on Straps

Place the aquarium/terrarium onto the straps and center along the length.

Step 3: Clasp Straps

Clasp straps, and tighten (no not over tighten remember it IS glass). Remember to center the handle on top. When carrying, for safety purposes, do not lift the aquarium/terrarium to far above the ground when transporting.

As a side note, chances are the single strap that is suppose to go around the case length wise will not fit around the terrarium/aquarium so remember to tuck it into one of the other straps so you don't trip on it while walking.