Add a place to enter your zipcode, so radius searches are accurate
AdminZiink (Ziink, Ziink) commented
The Chrome & Safari versions already have geolocation code to determine your location and uses that for searches. The Firefox version will have that too but in the meantime it uses the location of the primary Craigslist site you use.
However, since the data is always retrieved from Craigslist, the location information is only useful in selecting the right Craigslist site to retrieve data from.