It depends where you want to go?
South east asia is one place that comes to mind, very cheap and some excellent things to do. South America is another place, but a little harder in that very few people speak English here. I never took a guidebook to South America, I should have! Can´t speak much spanish but spanglish gets you by!
I´m not sure about the prices in S.E asia, but in South america you can get a 3 course meal for $1, and big bottles of beer for 80 cents. Transport is very cheap, busses charge around $2-4 per 100km. Accomodation for as little as $4 a night. I´m sure Asia is similar.
Flights are getting cheaper all the time, you shouldn´t have to spend more than 700 pounds on a return to South east asia or South America.
If your spending a month in one place, then you could look at volunteering in a hostel - you´ll get accomodation and usually a drinks allowance. It´ll also give you a bit of experience with bar work, and general "hostel" work - useful if you plan a low cost trip to Oz in the future!