If you've been down Tate Modern way recently, you've probably noticed some new additions to the river-facing wall: the Street Art exhibition, which we mentioned back in April, officially opens on Friday 23rd of May, and the pieces have been slowly but steadily revealing themselves over the past couple of weeks.

The tech-savvy Tate staff are live blogging as the artworks go up, and getting the artists themselves to throw in their pictures too. The work thus far looks interesting: in particular, Parisian photographer JR's young man, aiming a foreshortened video camera like a loaded weapon at folk ambling across the Millennium Bridge, is likely to cause a double take from tourists as they gaze across the river from St. Pauls.

The other five artists, including Brazilians Nunca and Os Gemeos, Barcelona resident Sixeart, Italian Blu and New York collective Faile are also blogging their progress.

Once your neck gets tired of gawping up at the 15 meter high wall mountings, you can give your feet a workout: the Tate has come up with a Street Art Walking Tour, a gander around Bankside featuring the work of five Madrid-based street artists: 3TTMan, Spok, Nano 4814, El Tono and Nuria. Truth be told: we're not familiar with any of 'em, but go pick up a map in the gallery foyer and see what they're about.

And that's not all! As part of the UBS Long Weekend, Monday will see a Graffiti Research Lab in which the eponymous New York artists are inviting young people to create their own digital street art and see it projected instantly onto the building's front wall. Meanwhile, the 'Tate Studio' in the Level 2 Cafe will host artists, bands and DJs, with people encouraged to get involved in experimenting with different forms of street art.

Street Art, Tate Modern, Bankside, 24th May - 26th August 2008. Entry is free. Graffiti Research Lab is on Monday 26th from 7pm.

Image courtesy of lewishamdreamer's Flickrstream