Heidi Swanson is regularly recommends Agave syrup in her recipes at 101 Cookbooks and in Super Natural Cooking, and it is a natural sweetener that often comes up in vegan cookbooks (being safe for those vegans who eschew honey). I've never tried using it before, always thinking "well I've got plenty of honey, surely I don't need yet another thing to crowd my baking drawer." However, I'm on a mission to try to recreate the Puffed Wheat Squares of my childhood in a more health friendly format (meaning no corn syrup) and so decided to pick up a bottle of agave syrup at the store this weekend while perusing the baking isle. I've yet to try it in my Puffed Wheat Square adventures, but I can report that it is indeed an awesome pantry addition.
With a milder flavour and much less sweet than the local honeys I buy (or corn syrup for that matter) agave syrup is an excellent and easy way to add a bit of sweetness to a dish. Agave syrup has a much lower sweetness factor, but a really nice flavour to it, and it's very easy to pour/measure and dissolve into things (not nearly as sticky as some sweeteners). And, apparently it has a much lower glycemic index than other sugars. I've used it several times since I bought it now, in tea, in a spicy asian ginger sauce, in a salad dressing and in a tofu marinade. I can see where it would be particularly well suited to sweetening drinks like homemade summer iced teas as it dissolves really easily and isn't an overpowering flavour. There's a great little article about it over at Mighty Foods, along with some links to recipes that use it. I still need to try it out for my Puffed Wheat Squares and I'm not sure if you can bring it to a rolling boil like you can corn syrup, but when I find out, I'll let you know.