As everyone in SEO knows, links are critical to raising the rankings in organic search. Search Engines have become proprietary, and the key these days is relevancy.

The term 'relevancy' is thrown around quite often, but it essentially means that it is quality links to relevant web sites that contribute far more to search engine rankings than broad quantities of unrelated links.  Having links in areas other than your chosen subject may not hurt - if it's a high PR link you'll no doubt experience the benefit, but relevancy will always be the defining factor in SEO.

You may be able to quickly and easily assemble a large array of links on a lot of sites, but good links from 'authority' sites with a high PR within the same subject field are worth more in the long term. The definition of an 'authority' site is hazy at best, but any popular (and relevant) site should be your target in terms of generating good links.