Tony Fournier's Group Harmony site.

Doo-Wop Groups - Biography & Discography - This is Jean-Cristophe Piazza's site, containing (as it says) short biographies of groups, with their discographies (and links to some of their recordings). What the name doesn't tell you is that it's a treasure trove of group photographs.

Doowopheaven is Hans-Joachim Krohberger's blog. Each "article" discusses an artist at length, with photos and discographies.

45cat is a site for record label enthusiasts. Here you'll find hundreds of thousands of label scans, with all the label info printed for you in an easy-to-read format. You can search by either artist or label and all genres of music are covered. It's a site I use all the time. And, if you're into 78s, the associated site is called 78 RPM on 45worlds.

Harmony Haven (Jim & Nikki) - Specializing in information & photos on Vintage Rhythm & Blues and Gospel Vocal Groups.

Charlie and Pam Horner have developed a site for Classic Urban Harmony. You can find out about their R&B presentations, as well as share their memorabilia. Here, you'll find profiles of vocal groups, from R&B through Soul (with some gospel mixed in).

The Yesterday's Memories Music Shop - Eugene Tompkins (he's sung with the Limelighters, the Mellows, and the Morrisania Revue) has a music store in Atlanta, Georgia called Yesterday's Memories. Aside from Gene being one of the nicest people on the planet, there's something about the store's name that I like. You can email him at: Eugene's mailbox.

Lou Sylvani has updated his Times Square Records site. This should bring you back to the days of Slim.

Human Nature - Can't say I've ever been a big fan of a cappella, but these guys from Australia are phenomenal. Take a listen to their rendition of the Miracles' Ooh Baby Baby.

Lunch Break - Here's another a cappella group. These guys are fun. Take a listen to Old McDonald Had A Deformed Farm.

However, that's it. I know that there are hundreds of a cappella groups out there. Please don't deluge me with them.