hotspot software?

You mean "portal" software? (I.e., like you'll find at hotels. Upon connection, you are first directed to a local web page in order to login.)

If so, ZoneCD is exactly that. Cost is very reasonable; free.

Works great. I'm using it myself.

Doesn't have any features that allow you to set up some sort of mechanism for clients to purchase time though. If thats something you are wanting, poke around on ZoneCD's web site and do googles for "nocat portals". There are a few freeware wifi portals that allow selling of time (uses PayPal). I don't recall the names of these portals offhand.

Cheers,

-E