My other little robo-buddy
I bought myself a Roomba the other day (well, in late October). A 405, which as far as I can tell is just the general (and bottom-of-the-line) 400 available from iRobot, but with an included remote.

Rise, my loyal robot minion! Rise, and vacuum your foes!
I'm still not totally sure why I bought it. It was on sale in my store for a decent price (just over $100), though it was still way more than I usually spend on a whim. Heck, I don't even buy $60 video games until they go on sale. Still, somebody brought one into the department to ask a few questions when I was working and it got stuck in my head. I did a bit of research on my phone on my lunch break, and decided after work to buy one for myself. It was a little odd, I have to admit. Definitely one of the largest impulse buys in a very long time.
So, how well does it work? Actually, I was quite surprised. It took me about fifteen minutes to 'Roomba-proof' my room by tucking away all the loose cables and making sure it couldn't get under things it shouldn't be under, but once I did that, it was pretty much flawless. I hit the button (the only button) and it scampers off, sucking up all sorts of crazy stuff. The pattern isn't quite random and it certainly ends up in some places more than others (especially in my very oddly-shaped room), but it gets everywhere eventually in it's cycle (about an hour or so, though I usually let it run when I'm at work so I'm not sure). It never gets stuck in a weird corner or under a desk, and it moves from linoleum to carpet like nobody's business. When it finishes, the floor looks great, and all I have to do is empty the little bin and plug it back in. Eventually I may get the charging dock so it can do that last part itself, but that may just be the first step towards the inevitable robot rebellion. Best to keep them dependent on us humans for the time being.
So far I have really been pleased with the purchase. The floor is looking a lot better and is certainly vacuumed more often now that I don't have to pull the crazy old upright out and fight with its crimped hose every time. I run the Roomba every two or three days, depending on how bad the floor looks, and it does a fairly good job. I keep the floor neater in general (no large items left around, no loose cables, etc) so that I can be sure that the Roomba will run on its own, so my room is neater even before it is vacuumed. The only consumable to worry about is the battery (which should hopefully last a long time before needing replacement) and the filters (which are a every couple of month thing, according to their recommendations), so the long term costs should be pretty good. It may not work as well as a dedicated vacuum (bigger stuff is occasionally missed and it certainly takes longer), but I am vacuuming more often than I was before (it's so easy...), so the floor is better. Plus, I have a ROBOT THAT CLEANS MY HOUSE. This is the future, people.
Oh, and my first little robo-buddy? My Android, duh.