It's a fast-growing ground cover/vine, and I see it everywhere by the roadside here in Sioux Falls, South Dakota. It looks a lot like a Morning Glory, but the flowers are white or white with a pale pink blush, and only about an inch across and about that deep. The leaves are broad, perhaps three-four inches wide and almost that long. It seems to like dry ground and suneshine, and I usually see it in grassy unwatered areas, sometimes climbing up other wild plants, sometimes in low mounds (usually the latter would be a smaller patch, by the curb of a sidestreet; the former tends to be next to highways/freeways, though I have seen it like that in a trailer park).
They started blooming a week or so ago, and if they're anything like last year, they'll keep at it until school starts again.
I love these flowers/vines, but as I said, I have no idea what they actually ARE. @_@ And I can't very well write about them if I don't know what they're called, can I?
Thank you for your time. ♥
EDIT: Okay, thank you all! I'm pretty sure now that it is some sort of bindweed. Thanks for the help. ^_^