Cresyn's latest addition to their portable headphone lineup is the CS-HP500 headphones. Featuring a collapsible headband and supra-aural ear cup design these headphones are definitely intended for users on the move. The headphones sell at a very reasonable $39.99. For that price you get premium portability, but the downsides are many. The supra-aural design means that the cups exert pressure on your ears rather than on your skull.
Despite their relatively small size the CS-HP500 headphones come in a huge box. The folding nature of the design means that they can be twisted and folded into a more compact form which is great if you need to fit them in your already crowded backpack. Besides the headphones you get a fake leather bag to store them in.
The cable is not that well made, and even for a set of headphones worth around $40 it is cheapish made. Normally the cable does not matter that much on a set of $40 headphones, but for a set of headphones intended for use on the move the cable needs to withstand quite a bit of abuse, and the cable on the CS-HP500s looks a bit on the fragile side to me (hard cable jacket, not that flexible conductor ie. prone to conductors breaking inside the jacket).
The jack is likewise pretty cheaply made, but you get a 1/8" to 1/4" adapter.