As I mentioned elsewhere, I built a frame from pieces in the Land Defense Battle Pack set.
I'm calling it the Bullfrog.
I'm thinking it's a standard soldier loadout (2Rd/1B/1Y/1G/2W). It has a gun, an armored cockpit, a comm antenna, and those funky legs for attachments.
Back in May of last year I proposed the Single Set Challenge. This design almost qualifies. I had to use one extra piece from a second Land Defense Battle Pack.
Here's the Flickr page.
And the Brickshelf gallery.
Mobile Frame Hangar discussion topic.