The one concern I would have with using an open hotspot is that if you can get on it... so can anyone else. They don't have any security or encryption enabled... so all your traffic is available for anyone within proximity to sniff.

I use open hotspots when I'm away from my home... but I still VPN into my home connection for the added security. I don't want everyone knowing the contents of my email and what sites I visit. etc.

If you do decide to use the open hotspots.. maybe think about using some type of encrypted proxy. tor comes to mind. However, I'm not sure if traffic on tor is encrypted through the first hop or not... you may want to do some experimenting.