1. Thank you. Backformed slang from adding vowels to the Internet abbreviation KTHX, or "ok, thanks."
Thus far, observed as spoken slang only, although given the ironic usage of "kthx" in the first place, it may not be long before someone sweeps it back up into their chatspeak as part of the Internet's continuing dumbassification.
"I'm going to go clean the litterbox."