I once heard of someone getting an "infinite" bulb exposure with the XPan by combining the max bulb (9 min) with the multiple exposure setting. I have not tried this yet, but I'm curious enough to do so in the relatively near future. The logistical question in my mind is: if the method works, the new limiting factor becomes the batteries? I've found the batteries die quickly when using the bulb exposure since the shutter is held open by battery power.
The other question on my mind is: if the method works, and one is shooting stars in the background, will the star trails be dashed? Anyway, I'm curious to try because I've always wanted to make a celestial circle photo, and this is my only camera. Besides, if it's possible, just imagine how cool this will look with my 30mm lens!
For the record, I have the V700, and I think the results are great. However I am far from experienced, and haven't given it a whole lot of use yet. It's part of the 9% bill, too.