Honigs has long socks that are amazing under the shin guards. The Under armor soccer socks also do the same job, and if you have an Under armor outlet around or near you they are usually 3 for around 5 dollars.
I forgot my special compression shorts a few years back and put my cup in a regular sock and draped the sock over the top of the compression shorts and it has worked great ever since. I get a couple of strange looks in the locker room/parking lot when I change, but no one should be looking there anyhow.
