After reading various threads and looking around, I decided to give the T-Bag triple windshield bag a try on my 2010 SE Ultra. I'm very glad I did as it's nearly a perfect fit IMO. It looks like it should have come from the factory this way and its actually quite easy to install (even with the HD LED Windshield Light Bar I have installed).
I bought it on Amazon
http://www.amazon.com/Windshield-T-bags-Harley-Flhx-Flht/dp/B002N46XCU/ref=sr_1_12?ie=UTF8&s=miscellaneous&qid=1277903071&sr=8-12 although I believe there are less expensive sources. I received it in 2 days which was rather surprising.
The install at first seems like it won't fit but in fact in fits perfectly. After its been on the bike a while it forms to the windshield and becomes a breeze to take on or off if you need to open the fairing for example.
Just loosen the 3 bolts on the front of the fairing until the gap is big enough to slide the vinyl backing to the bag into the slot. You might also need to loosen the 2 upper inside fairing screws to get enough clearance. Once the gap is big enough you just need to slide it in and then press as hard as reasonable to get the backing to slide into the slot until the stitching threads are all the way down and even when looking through the windshield from the front. You then just tighten each of the front bolts while pressing down on the nearest bag to that bolt. Once the bolts are tightly screwed back in, the windshield bag is now secured. (don't forget to to tighten the inside fairing screws if you loosened them to get the bag into the slot).
You're now ready to ride. The bag is great for an EZ Pass transponder, gum, small flashlight, pocket knife, chapstick etc. Not so great for sunglasses as the side pouches are actually smaller then they look. All in all a great addition that looks like it was factory installed from either side of the windshield and provides a very nice storage addition.