Hi! This makes me happy to hear, because we haven't really found much. There is a meet up group in Boulder that meets every week, but we haven't been able to attend yet. It's hard for us to get out on weekday evenings because we have kids, as I'm sure other poly folk do as well, so it would be nice to have a mixer or something on the weekends.
There is a yahoo group that's called Colorado Poly Connections... it's been so/so, but they occasionally plan things in Denver too.
Keep me posted if you do start a group, we're REALLY itching to get out and meet folks!