Here’s a cute idea from one of the boffins at MIT – hold a time travel convention! After all, you only need to hold one convention as time travellers from all ages could attend the one event, as long as they found out about it. So now everyone is supposedly spreading the word so that one day in the future, time travellers will see the invitation and decide to pop back to 2005 to attend. I found the link via Instapundit.
Here’s an idea – anyone with an identical twin sibling could have some fun. One of you show up ot the time travel convention looking normal and sane, but complaining about how few people there are attending. Then your twin rushes in wearing a futuristic suit and tells there other self “You fool, the convention is in another parallel universe, not this one, they are waiting for me… us!”, and then rush out.