I picked up PAYG.us
PAYG is an acronym for "Pay As You Go" and is most commonly used w/ cell phones and w/ tax payment plans in some countries.
At this time, it is not a, particularly, popular search term so I picked it, (along w/ some other "PAYG" names), speculating that the acronym might catch on. It is pronounceable, it has "Pay" in the body and it shortens a 4 letter term. I have seen alot of recent advertising for "pay as you go" phones (using "Pay As You Go" rather than "Prepaid", which has been more common) and have, even, seen "Pay As You Go (PAYG)", used a couple of times so I felt it was worth the shot.
Some links:
http://en.wikipedia.org/wiki/Pay_as_you_go_%28phone%29 http://www.phatphones.com/Pre%20Pay%20Phones.htm
