Cisco OfficeExtend Alternatives (teleworker AP)

I'm currently looking for a solution for remote workers/groups like the Cisco OfficeExtend AP's, where we could give the group a preconfigured AP, and they simply go to their home or remote site, plug it into the internet and have all their corporate WLANs come up with VPN tunnels back to the office.

The Cisco solution seems pretty good, except for two things:

1. Needs wired connectivity

2. No support for captive portals (needs an unblocked internet connection, so probably won't work at most hotels or conference centers)

Anyone have any other suggestions for this type of solution, that would allow wireless connectivity and support logging into captive portals?

Thanks!