If the hotel is handing you an IP address, DNS info, and default gateway IP via DHCP, then any SOHO router (presumably including the latest router/wireless-access-point combinations) should be able to pick up the necessary info via DHCP, and you could simply use a machine on the internal network to hit the proxy web page in order to agree to the charges.
By doing this you could possibly allow others to steal the hotel's bandwidth. Won't a long Cat V cable cut it for a few days?
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Saving the world, one clue at a time.