You don't need wireless internet at home to do that - your home broadband has nothing whatsoever to do with wifi hotspots.
Some hotspots are free, others you have to pay for on a pay as you go basis, or by monthly fee. The two common ones in the UK are:
OpenZone
http://www.btopenzone.com/
TheCloud
http://www.thecloud.net/About-us/
Another alternative is a mobile broadband dongle, on contract or pay as you go. You buy these from Vodafone, 3 and other suppliers. These aren't reliant on wifi hotspots