Interesting, what Gurunet says (from AHD). I have to say, I hadn't realized it was alloneword.
an·y·more (ĕn'ē-môr', -mōr')
adv.
1.
a. Any longer; at the present: Do they make this model anymore?
b. From now on: We promised not to quarrel anymore.
Chiefly Midland U.S. Nowadays.
REGIONAL NOTE In standard American English the word anymore is often found in negative sentences: They don't live here anymore. But anymore is widely used in regional American English in positive sentences with the meaning “nowadays”: “We use a gas stove anymore” (Oklahoma informant in DARE). Its use, which appears to be spreading, is centered in the South Midland and Midwestern states, as well as in the Western states that received settlers from those areas. The earliest recorded examples are from Northern Ireland, where the positive use of anymore still occurs.

For reasons lost in the mists of time, I have the idea that saying any longer is the grammatically correct version.