Image from Wikipedia, more info at the main article. Following are the names of Norse dwarves from various sources: Nyi, Nidi, Nordri, Sudri, Austri, Vestri, Althiolf ("Mighty Thief"), Dvalin, Nar, Nain, Niping, Dain, Bifur, Bofur, Nori, Ori, Onar, Oin, Modvitnir ("Mead-Wolf"), Vig, Gandalf ("Magic Elf"), Vindalf ("Wind Elf"), Thorin, Fili, Kili, Fundin, Vali, Thror, Throin, Thekk, Lit, Vitr, Nyr, Nyrad, Rekk, Radsvinn ("Swift in Counsel"), Draupnir, Dolgthvari, Hor, Hugstari, Hlediolf, Gloin, Dori, Duf, Andvari, Heptifili, Har, Siar, Skirpir, Virpir, Skafinn, Ai, Alf, Ingi, Eikinskialdi ("Oak Shield"), Fal, Frosti, Finn, Ginnar. (List from Sunnyway.com) See also verses 11-13, here.
I was reading through the book of Norse mythology that Dana lent me, and while I generally tend to blank out over lists, especially long ones, as I skimmed over the list of names of the Norse dwarves, I was suddenly on alert: many of these were quite familiar to me! Skim over the list above and see if you can tell the connection I came to quite quickly.
For a hint, note that about a third of the way through, one of the dwarves is named "Gandalf," or "Magic Elf."
As it turns out, Tolkien used the names of the Norse dwarves as the source for the names of the dwarves in The Hobbit and the LOTR. Here are the names of the dwarves in The Hobbit, from Answers.com: Fili, Kili, Oin, Gloin, Thorin Oakenshield, Dwalin, Balin, Bifur, Bofur, Bombur, Dori, Nori, and Ori. There are two names in that list I don't see in the first (Balin and Bombur), but I was quite surprised I hadn't realized this until recently.