One of the comments elicited by Zeiss's response struck me as a bit unfair. Zeiss said it did not have a list of references from those using their confocals. In reply, someone said that Molecular Probes maintains a beautiful data base about the use of its chemicals, so why can't Zeiss. I don't argue that Mol.Probes is doing a good job, but all they do (I believe) is search the literature using their chemicals as key words: we all often put those key words in the abstract or our key word list. If we want Zeiss (or other vendors) to track their users, we have to start using their names in the parts of manuscripts which are placed in databases (eg. author-defined keyword list). This actually doesn't sound like a bad idea to me, as we all benefit. Any comments? Chip Montrose Johns Hopkins Univ.