My heaviest item is my sleeping bag. It is super though, and is actually a 3-part system: a goretex bivvy sac, green "summer" sleeping bag, and black "winter" sleeping bag. It's a military issue thing. Needless to say, using the three parts together suffices for arctic conditions.
http://cgi.ebay.com/ws/eBayISAPI.dll...m=280017932167
But with my Hennessy hammock, I use one of those silver shiny heat reflector pads that weigh almost nothing in place of the black winter bag. I just started doing that on my most recent tour and couldn't believe how warm the reflector pad kept me when in the hammock. I can't recommend it enough.
I have a tiny Esbit cooker, but I don't use it often. Spending €3 for a hot, fresh Döner Kebab sandwich is money well-spent. And it is my only expense since I don't stay in-doors at night. I alternate sleeping in the woods (stealth camping) and sleeping at campgrounds. If more campgrounds offered "shower-only services", I'd stealth camp every night and use campground showers.