OTL is a stick figure
of a person on all fours. O= head, T = arms on the ground, and L = legs. The lowercase form is orz
This emoticon can be used interchangeably with *worship* which simply means that you are grateful to whomever you present the emoticon to. You use it on someone you really look up to, or someone who just gave you valuable information, or someone you just want to be like.
In some Asian cultures, the emoticon symbolizes crawling, and can indicate frustration, desperation, or even despair.