Here’s a quick one: check out Cloudnymous when you get a chance. I just signed up, and I quickly gave them $50. Until December 2nd, this actually generates $100 in credit.
I don’t actually end up using VPN services all that often, but what makes this particular company unique is the very dynamic way in which it allows you to pay for service. You can pay by the day, by the month, or by the amount of traffic you want to transmit. These different scales are all tied to different servers, so you can keep the profiles configured and connect as you see fit. On mobile, for instance, you can set yourself up with a traffic paid server, while keeping others on a monthly or daily plan.
The other side to this service is that there’s a free tier, too. You can connect up to one hour per day, and while these servers are a lower tier without the same promise of bandwidth as the others, I was able to get plenty of throughput in some rather aggressive bandwidth tests.
If nothing else, it’s a good thing to have in your tech tool belt, for when you’re stuck with a public WiFi connection or a friend’s not-very-well-managed network.