Site-specific protein labeling with synthetic dyes is an emerging technique for live cell imaging. A protein or peptide tag fused to the protein of interest provides the means for attachment of a fluorophore or other small molecule probe, to allow non-invasive imaging of the dynamics of protein localization. The past two years have seen significant advances in such methods, the publication of a number of new tags for labeling, and the imaginative application of established techniques to tackle previously intractable biological questions.