I saw Mat Collishaw's current installation at the BFI and cannot recommend it enough. Its a crazy wooden structure like some strange central European cupboard where the mirrors also double as tv screens. The mirrors change from reflecting to showing images that I think are from the late Georgian/Armenian film director and artist Sergei Paradjanov. On April 13 Collishaw is doing a talk at the NFT3 (620pm, need to book). I'd be there if I wasnt in Berlin that month!