Not sure how many folks do this, but I'm now in the habit of searching "daily deal" sites before my foreign trips to see if there are any useful offers. Groupon and Living Social are pretty universal these days: like I just bought a rafting trip in Malaysia. And I've used them for restaurant meals in Europe and Australia. I'm pretty picky with what I buy -- given that it's pretty much use it or lose it -- but I haven't had a bad experience yet. It's actually gotten a little easier to find the deals these days, as the offers used to be "live" for only a day or so, but the new business model seems to keep them alive for weeks, so you don't have to be that vigilant in checking for them.

For Groupon itself, the trick seems to be to pay by paypal. I haven't had any luck paying direct by credit card. To get it to work, I first log into paypal on my computer, and they go to the groupon site to pay (selecting paypal, of course). With livingsocial, I've been successful just using my credit card.

To find local daily deal sites, I usually google something like "Sydney daily deals" and there's often an aggregator who collects all the offers from the different companies.