As it turns out, I have only ended up being a lightweight backpacker (my typical baseweight is perhaps 15 pounds). My total packweight, with a weeks food and no water is usually around 30 pounds. On a recent trip in the Sierra I began with 26 pounds and made my exit with 19 pounds.
You can pick whatever point you want on a spectrum from ultralight on one hand to conventional backpacking on the other. Striving to be ultralight is a good goal whether you actually reach it or not. Lightweight backpacking will drastically improve your enjoyment outdoors. Actually being ultralight can become a game and end in itself. I am sure the true ultralight folks are having a great time, but I have picked a not quite so extreme point on the continuum.
I once met a lady on the trail struggling with a big pack and while we both stopped for a rest, spent some time sharing my ultralight enlightenment. Her response was, "Oh, but I want my comfort". I thought about this afterward and thought that my response should have been, "OK, but when and where do you want your comfort?" Going lightweight gives me comfort all day long carrying that pack. And I sleep comfortably too, and eat well, so I don't really think I have done anything but improve my outdoor experience. A lighter pack enables you to hike farther and faster and visit places you could not have reached before, and with more joy.
There are people out there doing multiday trips with 16 pound packs! Not me (yet!), but it definitely sounds like the thing, and I am eagerly learning more.
The guy who started much of this is Ray Jardine. I am impressed with Ray and Jenny, and enjoy their deeds and writing. (Read their book: Trail Life).
A great resouce is BackPackingLight.Com. ($24.99 for a years membership - As much as I hate the pay to view concept, I joined, and it was worth it).
Another interesting site is Backpacking.Net - ultralight.
Famous in the history of ultralight backpacking is Emma "Grandma" Gatewood (1888-1975). She hiked the Appalachian Trail twice (once around the age of 80) with plain tennis shoes, a pastic shower curtain for a tent, and with food and spare clothing in a bag carried over her shoulder. Her immortal words:
Most people are pantywaists, exercise is good for you.
My goal is to achieve what Ultralight Joe has achieved.
Someone said that you probably don't want to go SUL very often, but doing a trip or two that way will really teach you some lessons. This makes sense to me, so I will probably take the challenge and try it on a short trip or two. Up till I heard this comment, I figured it was just for crazy extremists, and perhaps it is, we shall see. Heck, I should just try to do more bonafide ultra light trips.
There really does seem to be something significant about the 30 pound packweight. I recently got sloppy and did a trip with a 35 pound pack and was back into the same old misery and suffering. Anything 25 pounds and under I hardly notice. A 30 pound pack is mildly unpleasant at the start of a long trip, but I know it will be just fine after a couple of days.
Tom's hiking pages / tom@mmto.org