Question : Connect 2 Internet connections to a single network

I have a 5 PC, no server Windows XP network.  The copmany I franchise from provides me a T1 to the main office for my Point of Sale application.  It allows internet conenctivity to only Industry approved sites (It is a paint store, so I can look up info on paints or blinds, but not maps or bank accounts!).  I got a yahoo SBC DSL standard 2wire wireless router and a laptop that accesses just the DSL.  

I would like to make this work on all my pcs and maintain my POS access but route the internet via the DSL.  I do not want to do multi-homed or double nics as I only have a single wire to each PC.  I guess I could go wireless with a second NIC, but I would prefer not to.

How do I do this, Static Routes, 2 Nics, a good router.?

Thanks

Answer : Connect 2 Internet connections to a single network

Does the POS application use direct internet access or proxy? If it uses proxy then you don't have to worry as your clients would go through default gateway and use DNS.

If your POS app doesn't use proxy and uses direct connection, then delegate one PC as a proxy server, install a nice but cheap proxy app on it, route your clients through that PC as proxy clients (set in internet explorer) and your proxy server will link to your DSL/yahoo but not to your T1 thereby leaving your T1 and frnachise clear.

Sorry about my little mistake :(