Thanks to a mention by Sean Levin over at the Crossover Universe blog, recently I have discovered a website that promises to be both entertaining and useful. It exists under the name Sherlock Holmes Pastiche Characters, although (as the introduction states) at this point it's really more an authoritative, if not quite exhaustive, guide to Sherlock Holmes pastiche works themselves. A remnant of the site's original purpose remains, however, in a list of "Historical & Fictional" characters - this last a great boon for the crossover researcher, especially in cases where more than one author has crossed Holmes over with the same character (perhaps not surprisingly, Count Dracula has his own page).
non-canonical family members of Holmes and Watson is especially interesting), as well as the modestly named Indexes to Classic Sherlockian Works. This last may be the greatest page on the entire site, for two of the works that have been painstakingly indexed are none other than Crossovers I and Myths for the Modern Age. Just those two would be a find - taken as a whole, the site is a treasure trove comparable to the Agra treasure, and great thanks are due the hands that built it.