i have loads of adaptors, they are cheap and can be bought practically everywhere for around €1. i also boughta 4 way extension lead in spain which i take with back me in case there are only a few sockets in the room. best place to pick them up though is usually an ironmongers (Ferretería). which also usally have things like pegs which can be v useful.
although in principle i cant see what's wrong with your mates idea. on problem would be that the trip in the room may not like being overloaded with too many things!

Spain is pretty basic when it comes to electricity and wiring. I have seen appliances wired in to the mains with wire that I would regard as only fit for wiring a doorbell! I have also been in accomodation where you could not operate the second electric ring on the hob unless you turned off everything else elctric as the circuit breakers overloaded.

What are you planning to take that needs power?

Probably the most powerful item would be a hairdryer which could be as much as 1200 watts. I doubt a phone charger or radio would overload a circuit.

Basically just hairdryers and straigtheners and a radio the important stuff ya know! I think a plug board would be quite cumbersome to carry. What sort of adaptor do we need.

A standard 2pin out European adaptor will suffice - you can get them at the airport if all else fails!
Martin