So I tried the heat shrink tubing for hoods on my sram red shifters. It's on there now- I'm hoping I've learned a bit and the next ones will be better- I have to get some pics up, but I did mine mounted to the bars- otherwise I'd be cutting a hole in each of the hoods in order to tighten them down to the bars. I had a couple of creases which are workable, but not the prettiest thing. Weight-wise they're ok- I don't know if I was using thicker tubing but they started out at 23g each (unshrunk) and after heating and cutting excess they came in at 14g and 15g. The btp hoods weighed about 26g, but these should last a lot longer and they're much, much, much cheaper.
Another issue I found is wrapping the bar tape, I probably need to leave a bit more tubing on the edges so I can get the tape under there- even better might be to wrap the bar first and then shrink the hoods on there.
The lightest alternative seems to be self-sticking silicone tape (hoods and bar)- since I experimented w/ it a bit, when I took off the last incarnation it weighed about 29g for one side of the bar, but remember that's covering the hood as well. Issue here is it's being wrapped on the shifter and the silicone tape starts to come undone- in my case, after about 3 weeks. It's also ugly, really ugly.
The shrink tubing is a lot neater- in the end I'm not sure if it's worth the effort- I'll have to see how long they hold up and how the next attempt comes out.
At least I didn't melt my powercordz w/ the heat gun!!!