A few years ago I made a presentation at an ad agency in Tokyo. The agency used a small Sony projector that really impressed me. Although it was not the smallest or the lightest on the market, I loved its slim design and it was very bright and made the slides on the screen look fantastic. Last month I finally purchased a Sony projector in the same family as the one I used that day in Tokyo, the Sony VPLCX21 LCD Projector. It's just around $1000 and for that price it's very bright (2100 lumens) and crisp. It has a native XGA Resolution of 1024 x 768 which is all I need. It's only 4.2 pounds and fits easily into my bag along with one or two MacBook Pros. Even if the venue says they will provide the projector, I carry this along now just as a backup. It may not be the best on the market — I have not done a lot of research on projectors — but it's a great combination of a good price, high quality and bright, and relatively small and light. And, hey, it's a Sony. I'm really happy with it. And because it's so thin and low, I can put my MacBook behind the projector at the same table (larger projectors would obscure the computer screen and I'd have to find another table or put the computer on the floor — remember that the computer screen is acting like a monitor.)
In the picture above you can see my wife as she delivers the first part of a presentation on branding (I took the stage after her part). Note the position of the projector and the brightness of the screen even with most of the house lights on (though this pic does not do the screen justice). The room was a medium-size ballroom seating about 100 people (photo taken with the iPhone). Note to my buddies at Microsoft: yes my Microsoft guest sticker is still bonded on the front cover, as you can see — d'oh!
I purchased my Sony on Amazon.com for $1027; it may be cheaper somewhere else. (Please feel free to recommend other good, light, and bright projectors for those of us on the road.)