The quantum imaging paper has been published online as M. Tsang, Physical Review Letters (Editors' Suggestion) 102, 253601 (2009). See also the accompanying Viewpoint commentary by P. M. Anisimov and J. P. Dowling, Physics 2, 52 (2009). Physics is an APS publication that "highlights exceptional papers from the Physical Review journals." Also I have posted a longer paper on quantum smoothing on the arXiv (arXiv:0906.4133). This is an extension of my earlier quantum smoothing paper (arXiv:0904.1969), which will appear in PRL this week as well.