shopping

I am looking for a device similar to a MiFi but not for a wireless cell
phone network.

I am in a conference room with only one (working) jack. Or I am at a
friend's house who has wireless encrypted, but for the life of them can not
remember the encryption key/password. Their router is in a room where the
action is not so I can not just plug in.

I can use an access point but I'm actually looking for something smaller and
more portable that can even run on batteries. This device would either plug
into an existing single network drop or connect to a PC via USB and make use
of ICS (Internet Connection Sharing) or both (not at the same time, of
course).

Does such a device exist yet?

~alan