Money-saving tips around London for our poor American cousins...!
(Perhaps others can add more or give tips for elsewhere in UK.)
1. Instead of shopping on Oxford Street, try one of London's many fabulous markets, eg Portobello Road market
2. Many museums, as noted previously in this thread, are free (apart from special exhibitions). Check them out.
3. Everything is much more compact (ie... crammed into a smaller space) over here. That means you don't always have to use public transport or an expensive black cab to get to where you want to. Walking is good.
4. London's parks and green spaces are a feature, very central and free. (I spent Sunday afternoon in St James' Park, and made some new friends who had purchased a frisbee for just £1 | $2 from Lilywhite's in Picadilly Circus.)
5. Lots of Subways over here now. Good for a cheap, wholesome sandwich lunch. You may have heard of them.
6. We have summer clothes sales in high street shops some time around June. Don't know if you have these across the pond or not?
7. Currently several free newspapers come out every day and are given out on every street corner. DON'T believe all the news in them, they're pretty trashy. But you'll probably find some special deals in them.
8. Lots of pubs and bars have a 'Happy Hour' in the late afternoon, say 5pm-6pm. Drinks are cheaper during this time to encourage trade during the lull. Again, maybe you have this Stateside too - not sure?
9. There's a ticket booth in Leicester Square that does reduced rate theatre tickets for West End productions. Never used it myself, but it's been going for years and you might pick up a same-day bargain. Pack nice clothes.
10. A walk along the South Bank from Waterloo to London Bridge, with a visit to Tate Modern and St Pauls (over the river), is pleasant with lots to see... and free. Street performers, views of river and city, cafes and restaurants on the way, London's bridges etc. You could see a lot and fill half a day this way.
11. Many central London churches stay open each day and are free to visit (donations invited). We know y'all love that cute British history thang.
12. Finally, why not MAKE some money by importing some Apple kit and selling it to your Brit friends? They'll get it cheaper, and you'll make a profit. Maybe not much, but an idea for the enterprising!