I haven't tested with inverse domain names but I do have websites with exactkeywordnow.com domain. Meaning I just add some words behind the exact keyword be it now/guide/fast etc. As long as you have the exact keyword in the domain, it somehows provide some edge over having a non-keyword domain.
Recently, I just bought a keywordnow.com domain and has 15k exact searches per month in the health niche. Currrently, its ranking #8 after a month and the only offpage SEO I did was 100 social bookmarks, a couple of .edu contextual links and a blog network service on WF that posts to 400 different domains.
I am now starting my 2nd wave of offpage SEO by getting better quality links such as high PR comments, article submissions from high PR site etc and I should be in the top 5.
So, yes I think inverse domain does work in my opinion but why not get a domain name that makes more sense. Just do like what I did by adding words such as guide/now/fast etc behind the keyword and its equally effective if not better than an inverse domain.