I have 3 IR range sensors on hand that I will probably grab first and place on the front. I kind of like the Laser range finder too so I may move the 3 IRs to the bottom for detecting stairs, etc. I also want to mount a web cam on an RC servo gimbal on top. Initially, it will be a remote control robot via wifi. A web page will contain the webcam video and have some controls to move the bot. After that, I would like to make an iphone app that does the same thing, sweet! After that, I will mount a motion detector from a security system. This motion detector will simply trigger the robot to power up from sleep, track motion with the webcam, record to remote location and page my phone. Thus, I will have a simple security system. I could also add a very loud alarm perhaps.
Next, I want to go autonomous. My whole interest in robotics is not so much mechanical as it is about creating AI. Since I was a kid, programming in grade 3, I was interested in how everything works, electronics, mechanics, physics, but most especially the brain. I'm going to digress from your question, but when I was in grade 9 I learned how to hypnotize, mostly from closely watching the stage hypnotist Raveen. That only fueled my interest when I delved into the depth of my friends' minds. One in particular (much later in life), was most interesting, his mind was an enigma, ...highly suggestable, highly creative, an internal representation of the world much richer than most people, and yet, personality disorders bordering on multiple personalities and dilusion. For example, he was the only subject that talked about his conscious self in the third person. It explained a lot of peculiar behaviors in his life, but he did manage to "keep it together" generally. I hypnotized a lot of people, but his was a unique experience, I feel it also gave me some insight to how the brain worked. Probably, the nature of the brain will be revealed to us through the ones that don't work as opposed to the ones that do.