Most of those places just have a local place put something together and deliver it.
Just call a local place. You get a better setup for less money (1-800 flowers isn't getting their cut), you keep the money local, blah blah. Plus after you've used them a few times, they recognise you and hook you up.
Some of the places will actually send flowers from their own place via FedEx/UPS. But you'll probably score more points by having an actual flower delivery guy show up, then a box coming in the mail.
Did you fuck up with your wife/gf or are you just stalking a chick? ;-)