kaysbelle,
I'm so glad you like my feeder!! It started out almost as a joke, but the hummers took to it very well and I was surprised how easy it was to maintain. I have a 2008 model in mind to build this winter, it'll have a few changes, but will be basically the same design.

You should be able to find a 1 1/2 x 1 1/2 x 1 tee at HD, but if you can't, you can use a reducer bushing to step it down. Look on the inside of the tee and you'll see a ledge which serves as the stop for the PVC pipe, that is what the lip of my bottle rests on. The lips fits so snugly in the tee, that I have to 'bump' it lightly to dislodge it when taking it out. In fact, I had to use my Dremel motor and a sanding drum to take a little of the glass off before it would go into the tee. In this picture, you can probably tell it's been sanded:

The orange tape helps keep it stable. The wire nuts are 3" apart (good guesstimation!) and are not staggered. The perches are 1/4" oak dowels - $.89 for a 3' piece.

I haven't used my feeder in three weeks because I've been taking census photos, and the hummers which are perched on the side opposite to the camera can't be seen. This weekend, just for fun, I'm going to put it back up and hang all my other feeders around it to see if the hummers show a preference. Please feel free to ask more questions, DIYers have to stick together!