you'll be lucky finding casual work in Portugal, its a very poor country and there's generally not enough work for the locals let alone foreigners who don't speak the strange squelchy Portuguese language - this is why Portuguese nationals have gone abroad to find work for centuries - i know a lot of British travellers who've bought land out there and they all say its really tough making a living... I think you're best bet is the Algarve which is the main touristy bit where there's more English spoken and more chance of casual labouring or bar work... i've never busked in the street over there but i've played guitar in bars with a few friends and the owners generally kept us plied with alcohol as long as we carried on playing...
regarding busking in Spain ii've heard that its pretty difficult, i think you need a permit or you get moved on by the cops all the time - I think I read that in a thread on STP so maybe use the search function and you may find the post i'm referring to or perhaps Google it - sorry this is all bad news ! on a positive note the people in Spain and Portugal are usually friendly and helpful and the skipping (dumpstering) is easy....
