The forum I found first when trying to lighten up, and which is still my favorite, is The Lightweight Backpacker, www.backpacking.net.
If there's a regional hiking forum where you live, I suggest you use it. If there isn't any, consider getting together with other hikers in your area to start one. The one in my area, www.portlandhikers.org, started in 2006 as the result of 2 guys putting their heads (and a little cash) together. Now it's really big and has set up an excellent Field Guide describing local trails as well as an excellent forum. The two original founders are no longer with it, but plenty of excellent folk have taken over where they had to leave off! One of the best parts of these local forums is finding details on current trail conditions.