If you are going to limit yourself to inside the motel room, that
doesn't leave many options. I have tried a dipole across the room,
but with limited success. I would suggest a table-top loop: tryhttp://www.qsl.net/7n3wvm/mag-loop.html
I've had good luck with a dipole kit used outdoors. This has 25'
of RG-174 coax and dipole wires for all bands. The center insulator
is attached to the coax, and has thumb nuts for attaching whatever
set of wires I want to set up in any particular situation. (This was
developed for backpacking - you may want to use 50' of RG-58
instead, if weight and size are not limitations.) This gives you lots
of possibilities - I've used the 40m dipole wires as full wave loops
on 10m, and, in one case, combined the 40 and 80m dipole wires
as an open wire feedline for a 20m dipole strung off the edge of
a 300' cliff.
The other standard approach is the end-fed wire and a tuner. The
best ground connection I've found is an aluminum window frame,
but many of the newer buildings are going to vinyl windows.
You may be able to hang the wire down from the window, throw it
over the roof, or tie it between buildings. #22 stranded, insulated
wire is good - try grey or black if you expect to operate mostly
in the evenings.