Best HD Antenna-How to improve off-air reception??

Hi all -
Working into HDTV and was wondering about the best off-air options for receiving high def, and looking for any pointers. Anyone ever encounter any difficulties, or learn any lessons along the way they'd like to share before I embark on massive wiring ventures and installing antennas everywhere? Any tricks for improving HD off air reception? Wiring, directional? Also, any opinions on direct antennas vs omnidirectionals? Thanks!
No expert here,but I have read the standard roof mount; pointed t'ward the station's transmitter,is all that is required. I will soon find out. I have just purchaced the entire Direct dish,combo /over the air inc/ reciever,hdtv projector; Should all arrive within 10 days. Then I'll see how right the mags' are.
My advice is to not invest into HD Satellite receivers and off-air antennae. Even if you are doing the installation yourself, the cost is considerable and not worth the investment in comparison to the amount of broadcasting that is currently available.
My advice is to wait until your Cable Company begins airing HD to it's viewers. My local cable company will be starting to air shortly and is in the process of making available a set-top box that will work alongside it's digital cable box. The cost will be $300.00 to purchase or $10.00 a month to rent. Since my television is HD ready, I will probably be looking to rent. The reason being that set-top convertors will get better and cheaper, and it's best not to committ so as to leave your options open for the better stuff that comes down the pike.
This will easily take the hassle out of setting things up the other way, and is far more cost effective and consistent from a reliability stand point as well.
It has been my experience as an ex-installer that omni-directional antennae usually suck. Go to Radio Shack and purchase only the UHF section of an off air antenna if you are bent on going the other way. Also, if there is a wife acceptance factor to take into consideration, try to install the thing in your attic. I've done this many times and often got good results. It doesn't always work however, so you may have to install on the exterior of your home.

Good luck
Update on just the over the air local channels. Still waiting for my screen (No HD, yet). So-- this just refers to the local stations,going thru the HD tuner w/ my $19.95 on the roof antenna,-- going into my old Pioneer pro 119.I just can't believe how great the analog tv stations look.(using the S out) You get extra channel 2's same for 4 and 7's. (For HD use. I don't know how the actual HD programing looks. (Yet)--No improvment on the picture quality of the Direct Tv stations,till you get to use the component-out's. I got the Panasonic TU HDS20 tuner. If you have the HDTV and are a Direct tv subscriber, I recommend it. BTW, for do it your self folK, the dish change is much eaisier than the mags say.
Look at Stereophile guide to home theater. They ran 2 articles on it a couple of issues ago. I picked up a UHF only antenna for $40, and all of the San Francisco digital stations 55 miles away peg the signal strength meter. A simple good outdoor UHF antenna is all you need.