I ran across the following web site a few years ago that got me thinking light.

[link=http://webpages.charter.net/bobad/]http://webpages.charter.net/bobad/[/link]

Here is a direct link to the article

[link=http://webpages.charter.net/bobad/light.htm]http://webpages.charter.net/bobad/light.htm[/link]

I used the techniques described in this article and on the site to build a 3 lb 12 ounce Burrito.

[link=http://www.rcuniverse.com/forum/m_1676792/anchors_1857391/mpage_5/key_/anchor/tm.htm#1857391]Burrito Showcase[/link]

Note that I could save more weight by going to a lighter .32 sized engine, and smaller servos.