These are some of my favorites that I found interesting. I have done the peekaboo mittens and the Chemknits convert any mitten pattern to fingerless gloves. They work out well. I started the granny's gloves on Bev's website, but thought the cuff was a bit too long.
Convertible mittens patterns:
http://www.youtube.com/watch?v=PZ6x-bNo3KI
http://web.archive.org/web/200705082...s/peekaboo.htm
Sideways gloves patterns:
http://www.bevscountrycottage.com/knitgloves.html
http://www.northeastfiberarts.com/fr...waysgloves.pdf