Curiously, LSIDs pop up again:
What is also cool is that each species has RDF formated metadata associated with it via an LSID, see here for an example. It would be nice if each species had its own permanent URL, which would be arguably more useful than an LSID, but I won't go there :)
Actually, iSpecies doesn't link to LSIDs for taxon names (that's done through one of my other toys, the Taxonomic Search Engine). Perhaps it's time to link these two toys together?