Since I don't understand it in the first place, I better just give you an example:
Cracked.com example, says otherwise known as "the pettiest hobo crime this side of aggressive panhandling." (WARNING: site graphics could be NSFW, YMMV)
It's not the only time I have seen it but it's the only one I can find via Google Search
The usage that I've seen seems to indicate some sort of comparison. The example above seems to say that "where we live, panhandling is aggressive", but I can't figure out the exact meaning
Note: So far I think I've only seen this phrase in cracked.com itself. Perhaps it's some kind of inside joke, but I certainly don't get it and its usage seems pretty legitimate
EDIT: Mathias Foster gives 2 other examples: this side of the black stump and this side of the equator.