It turns out that the PLA filament I ordered hasn't arrived, so I'm very low on filament. Since I have very few decent prints already, my demo might be a bit of a let-down. Oh well ...
Anyway, even if my Reprap demo is not as good as it could be, there's going to be a lot of other cool stuff going on on Sunday - including a bike workshop, sitcom / comedy workshop, hardware hacking / arduino, "circuit bending", psychology experiments - and more!
So, even if not just to meet another Reprapper, it could definitely be worthwhile coming along anyway!
One more thing ...
If any Reprappers do come along and happen to have some 1.75mm PLA filament they can spare and are willing to donate, I'd really appreciate it (my hot-end can't take 3mm filament and I haven't tried ABS at all). I will pay you whatever you paid for it originally. As it stands, I only have enough to print a few tiny parts.