Business directory - hotfrog.com Hotfrog is also having regional directories like hotfrog.com.au etc.
Rather than doing one at a time, use the new citation tool from Whitespark, it will find the citations for your area and industry.
If you want a serp result only contains business directory, i would like to say that use advance search operator like intitle, inurl, allintitle, allinurl, etc..
Here are some US-based directories: SuperPages, InfoUSA, Yelp.com, Yellowpages.com, Localeze, Acxiom, InsiderPages, Local.com, Kudzu.com, Getfave.com
You can list UK-based small businesses (<250 employees) over at http://www.is4profit.com/business-directory.html - You'll have to wait for entries to be manually verified as they are quite strict on what is listed (i.e. no link text spamming - Business names only)
@2dragonsltd You're welcome. Yes, it's http://www.bttradespace.com/ which is like an enhanced directory - From what I recall it's quite good for businesses that don't have a website because they can set up their own "tradespace" and if you already have a website then you can use your tradespace to supplement it. I'm not sure what BT Tradespace is like now, there were a lot of issues with it 6/12 months ago and I actually gave up using it. I might revisit and see if there's been any improvement.