I read an interesting article yesterday talking about how keyword and key-word is read the same in the search engines, and although the article was nothing new to me, it did give me an idea to talk about picking the right domain name.
I always try to encourage my clients (if registering a new domain name) to find one that uses one of their main keywords or phrases in it. Its better if they find an expiring domain name that has some time, PR and back-links in its corner already. It will be much easier to market a site with an older domain name than a brand new one. You will already have instant credibility on the search engines. Granted it will be more expensive to purchase a domain name that is currently owned in most cases but will be worth the investment.
So, it really does help that the search engines read the domain names, and keywords as "keyword" and "key-word". The dash can help those wanting to be found for the domain authority (just by having the keyword in the domain) for example www.utahsearchengineoptimization.com and www.utah-search-engine-optimization.com would be considered the same, its just easier for people to type without the dashes. So remember that when talking to potential clients and having to explain to them where to put the dash marks! It could get annoying, and you could lose some clients that forget to include dash marks...
In any case, if you can find a way to purchase a domain name with a keyword or phrase in it (old or brand new), it will help you with rankings for that phrase, and could make things easier when marketing a brand new site. You will obviously still have all of the other elements to compete against such as age of domain, number of back links, ILQ (Inbound Link Quality) number, and what kind of exposure the other site already has, but following this advice will help a ton at the very least when getting started!