After some time of non-activity I built something realy tiny. Ut is made from home stock parts. Bug simply goes forward. When meeting an obstacle it goes 5 steps backwards and turn right. Then it resumes forward. Leke real live bug.
Here is video: http://www.metacafe.com/watch/9015397/tiny_ladybug_robot/
It stands on four main legs and two supporting legs which allows to move each pair of main legs.
Two linear 1,8g nanoservos moves main legs. One 2,9g microservo moves supporting legs.
At the head position is 10 cm IR reflective sensor.
At the back is 3,7V Li-Po 180mAh single cell. Somewhere below wires is 08M picaxe.
At the bottom is third servo and capacotors. Everything is mounted on single prototyping PCB.
Main legs have feet with good adhesion while supporting legs are well sliding on surface.
My young son made a coat for this bug to inprove the appearance :-).