Do you believe in ghosts?

Yesterday, me and a couple of friends went out for dinner. We went to Pepper Lunch, which had nice food. However, if you like your bean sprouts well done, please skip that place, or else order something without bean sprouts. While we were queueing at Swensen's after wandering around Taka, the talk wound its way round to the topic of ghosts. Do you believe in them? My two friends go by numbers - look at the amount of ghost stories and retellings of encounters with 'them'. While I wonder how many of them are seriously true, and are not hallucinations mistaken for ghosts, or simply creepy tales to scare an audience, I'm not a non believer in ghosts. On the contrary, I want to believe that some inexplicable mystery still exists in our practical, tech oriented world. But I've never seen a ghost. Why is it that we all choose to believe in something that has no scientific proof. Very possibly, ghosts are the one thing that most people sort of believe in, and crosses linguistic, cultural and religious borders. It is also something we don't often talk about.
So are there ghosts in the world? You tell me.

By the way, if you've walked past HMV recently...they are having a clearout sale. Some really good cheap deals. VCDs from slightly below 8 bucks. I still feel ripped off. Don't ask why.