The caming gear is where the opportunities for weight saving are the greatest. I've simply replaced some old heavy stuff with ultralight equivalents. My Tarptent Contrail is more tent than tarp
http://www.tarptent.com/contrail.html
My bag is a summer one weighting 1lb so if it gets cold I sleep in a primaloft jacket that weighs 11oz. That is good for spring and fall, but to be comfortable in winter my gear would be too light.
Over the last year or so I've replaced most of my gear with ultralight equivalents and that has got the weight down. Also limiting the volume of my bags made me think about what to carry and my empty bags weigh 2lb as I don't use heavy panniers. I could get lighter by using bags made of lighter material that "cotton duck", and going from wool base layer to synthetic, but I like the way wool performs when wet and the Merino wool shirts feel really good. As far as toiletries go I carry 2 or 4oz bottles of stuff like shampoo and skin cream and a small travel tube of toothpaste. This is enough for a couple of weeks and I replenish at a store or if I stay a night in a motel I take the small bottles of stuff they provide.
Here's the weight of the catagories.
Camping 5lbs
Clothing Carried 5lbs
Toiletries 1lbs
Bike Stuff 3.5 lbs. (mostly made up of lock 1lbs, inner tubes 0.6lbs and multitool 0.5lbs)
Misc Items (wallet, phone/charger etc) 2lbs
Bags 2lbs
Total 18.5lbs
Here is a picture of my setup and a blog from two folks who have a similar approach to touring