Somewhere for a visitor to sleep

Our first preference for dining on our narrowboat would be a raised pullman dinette (preferably with a nice big window or side hatch).  It would allow space on the half of the table against the wall to leave my laptop - I'll have to make sure I can easily access it to write my blog entries!   We also like dinettes so there would be somewhere for a visitor to sleep.

We've seen quite a few boats that we really like that have either a small table and chairs or a breakfast bar.  Our last pick of the week had a half dinette with seating on just one side of the table.  We don't mind this but it would likely mean the dinette couldn't be converted into guest bedding.

I've been thinking about alternatives and found this : http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230652658562+&clk_rvr_id=252340313305
Small enough to put in a corner and use as a coffee table, foot stool or extra seating.

What solutions have other boaters come up with?  Air mattresses?