How do I run a successful Ubuntu Hour?
Try and make it as regular as possible, that way you'll get to meet people more often but others will be able to pop in if they know it's going to happen so that it doesn't have to be pre arranged. In Ireland we have 3 of them running, Dublin is on the last Wednesday of the month and people chose that date and it's worked out well.
What we've found is by picking somewhere central to meet up, people can have a bite to eat, or drink and chat. Making it relaxed and not a formal event is key to making it fun and for it to happen again and again.
It's a fun way to explain/show people new features you've found in a casual way, so I've showed the Loco Directory and let people use my laptop if I was running the latest release.
Make sure everyone is welcome, if there are new less technical people present and the topics are getting too technical, talk to them separately or perhaps suggest techy talk for another time.
Above all just have fun and chat about your community. Ubuntu hours are about your local area and the people in your community.
I've always helped identified people's needs and showed them how Ubuntu's implemented those needs. My audience is usually Mac and Windows people - but it's the same idea. Spend a few minutes touching on the new features in 10.04 then let the questions begin. I've also found that spending a little time highlighting what you like and use it for is also helpful to show why you like/use Ubuntu.
Try not to (as I've made the mistake in the past) to be THIS IS > ALL OF YOUR ALTERNATIVES as it's usually frowned upon.
The way we run our Ubuntu Hour is basically one of a very relaxed social interaction. No one needs to talk about Ubuntu if they don't want to and we generally let the flow of the hour or two take us to random places.
Basically we just enjoy each others company.
It's important to not put too much of a burden or expectation, those kinds of more targeted events should be saved for specific things, like the Ubuntu Workshops etc.
Oh and make sure you pick a location that members can get to.