Website Pros has a free one available from the control panel in Fusion.
There are also, many, many counter scripts available.
Look at www.hotscripts.com
FYI: counters are rarely used on non-personal sites these days.
They tend to be not very accurate and are easily skewed to make it look like more visits than there really are.
Or faked completely.
If you want accurate numbers for site visits and more, you need a good stats reporting program that analyzes server logs.
Most non-free hosting accounts include some sort of stats package.