Jebeld17, we really need more information. For instance, how is the plant "obviously ... related to the tomato"? Leaf shape? Fruit? Something else?

It would help if we could see a photo. Here's how to post one on GW:
http://forums.gardenweb.com/forums/load/hosta/msg0513322013993.html?14

Then if you don't get an answer here, try GW's Name That Plant forum.

Some nightshades have white or whitish flowers; they tend to have dark, not-furry leaves.

I've never grown eggplants or peppers, but I believe at least some have white flowers.

Tomatillos and ground cherries have cream-colored flowers, mostly with wine-brown in the interior.

You didn't say anything about spines, so I won't mention the nasty ones.... Horse nettle's the only one I remember having small white flowers.

You could search Google Images for the above; you might want to add "flowers" to the search terms.

You might try Googling the genus Solanum. There are many species in that genus, only one species are tomatoes, which wouldn't have white blossoms, potatoes and eggplant are also in the genus Solanum but there are many many other species that are in that genus as well.

Trying to track down exactly what you have will not be easy, it could help if you saw some fruits and what color they turned out to be.

Carolyn