This is a bit of a 'gray hat' invention.
On the outside, this looks like a regular wireless adapter with antennae and ethernet ports for you to plug your laptop into.
In the 'ethical' mode of operation, this router would give you your own IP address via DHCP, find public wireless access points,
and connect to them, routing your traffic over multiple points at once.
In 'gray' mode, it has scripts to click through web agreements, etc. for 'blessed' public access points.
In 'dark gray' mode, it actively scans the networks and uses something like Aircrack to get WEP keys, heriocally allowing you to keep your connection.
While I do NOT advocate anyone implementing the last mode of operation, it might be useful in a context where you ABSOLUTELY need to stay connected, and do not have time ask for permission (situational awareness for a search & rescue team during a disaster, etc.)
For applications other than web browsing, having a VPN to connect to that's tolerant of the source IP of the connection changing all the time might be necessary (I do not know if any existing protocols handle this, but they could be written).
This device might be implemented as a battery powered mini-ITX box running some sort of embedded Linux.