Many of the plants in bloom right now have white flowers. Due to time constraints, I limited myself to five species. (We don't have high speed access here in the swamp. I must depend on my dail-up connection, which on a good day provides me with the blazing speed of 24.0 Kbps.)
Sweetbay (Magnolia virginiana) -- aptly named, it has a pleasing fragrance.
Persimmon (Diospyrus virginiana) -- produces a sweet and nutritious fruit in the fall. Better be sure it's ripe before you taste it, though. If it is the slightest bit "green" it has a dreadful desiccative effect on the inside of your mouth.
Elderberry (Sambucus canadensis) -- If you look closely, you can see two spiders lying in wait for a hapless insect to pass by. These flowers are not exactly fragrant by human standards, but myriad little insects find them quite attractive. (On closer inspection, I believe the "spider" in the lower right may actually be a harvestman [Opiliones], commonly called a daddy-longlegs.)
Some people make wine from the berries produced by this shrub -- I've never tasted any, but I'm willing to give it a try.
Climbing hydrangea (Decumaria barbara) -- a common flowering vine here.
Common yarrow (Achillea millefolium) -- an herb that grows along roadsides and field edges.