Time to visit UK again?

I plan to visit London and Cambridge on 16-22 May. Just for sight-seeing and meeting friends — no business this time.

Plan is to meet old OpenedHand fellows, some old friends from Poland, maybe visit Canonical office just to see it (as I work for them for nearly 3 years). And of course see something cause I was few times in London but managed to see only train/metro stations and nearly nothing more.

Then Cambridge for 40th Cambridge Beer Festival. There are friends to meet as well and maybe see something as well (but here I saw far more things than in London).

As usual flights from/to Berlin to one of London airports (plan to return from Stansted as it is the easiest to get there from Cambridge). Need to sort out some places to stay.

Also have to check which UK prepaid is useful today. I need few gigabytes over HSPA — previously Giffgaff was fine for it for just 10 GBP but they have changed rules. Tethering required due to tablet and Chromebook (which I plan to get repaired or replaced).

Any suggestions for 3G or place to stay?

cambridge linaro travels ubuntu