Sony has launched PlayStation Now in the UK. It costs 12.99 a month and gets you access to more than 100 PS3 games that you can stream to your PS4, PS Vita, and PS3. If you don't want to pay monthly you can rent games for 2.99 each.
You can try the service out for a week for free but after that you PSN account will be charged.
You can read more about it over on the PlayStation page.