well i made one for storage.. and also made one to take stuff with .. i knit it and then felted it .. i know its not very bikerish .. LOL.. and you can sew one..i made a sewn one out of vinyl..just small but if you wanted something smallish.. you could use a small pencil bag type thing ..
I had the same problem-needed a place for small stuff (cigarettes/clipon sunglasses, cell phone) that was handy but out of the way. Best place looked like the bar across the windshield.....went to several dealers and found that Harley makes bars for different windshields for the "real Harleys" with two small bags mounted on them;but not for the V-rod windshields ( nice support! ).
I finally broke down and bought the "bags on a bar" for a '04 V-rod windshield that they had in the back room, and it wouldn't fit the '07 windshield. They have just recently taken down the V-rod "wall" at that dealership due to 'slow sales' ( nice support! ) and got it at a discount (normal price is around $80, got it for $62).
From there I drilled out the rivets and freed the bags from the bar. Only one bag would fit the area available behind my windshield. With the rivets gone, the little plastic liner cup comes out. Went to Micheal's (Craft store chain) and in the small leather crafts area got heavy needles, heavy waxed string, and some chrome snaps. Had some black nylon webbing lying around the house. Used a small nail set to punch holes through the leather and sewed two strips of the webbing to the back of the bag with a space between them to accomodate the Harley emblem buldge in the middle of the bar, folded the webbing over the top of my windshield bar and put snaps at the bottom, thus making a loop over the bar.
I can't sew worth a hoot, but the webbing hides my mistakes on the outside and the plastic cup, resecured with more snaps on the inside, hides my lack of skill on the inside/backside.
Result? Very secure, looks factory, even has the Harley emblem embossed on the flap. You could cover the chrome heads of the snaps with black nail polish for the total black out look but I like the chrome accents.