Perez Hilton got the London Wireless Festival ball rolling this morning.

Other celebrities and attendees soon followed suit; tweeting on-the-scene reports and lots of awesome pictures from the open-air concert smack in the middle of London.

Drake tweets his love for London.

And Serena Williams.

More reports from the ground.

This fan is a bit disappointed, however.

Oh, the humanity!

Well, no vodka and all.

Twitchy will monitor the concert and bring your more on-the-scene reports and photos.