I see no harm in using static DNS addresses. I've used Google public DNS addresses in the past just because they are easy to remember:

8.8.8.8
8.8.4.4

BTW, OpenDNS addresses (the free ones) are:

208.67.222.222
208.67.220.220

It's hard to imagine that there's much risk from using an unfamiliar DNS server, simply because most DNS servers are automatically updated from reliable sources. I suppose someone could monkey with the tables to direct you somewhere you don't want to go, but they'd be found out quickly in a public hot spot. Most problems with bad redirection come from malware or altered HOSTS files, not bad DNS tables.