The answer depends a little on what effect you're aiming for. You're unlikely to see much tangible SEO benefit from linking to the same word multiple times from a single page - once will perhaps do the trick.
There's also the editorial side, which might make multiple links to the same page burdensome - you could easily end up with more links than actual text on a page, which (if nothing else) would seriously harm legibility.
From a copywriting point of view, you might want to link every occurrence of words relevant to important pages, since readers are likely to both scan the content, and jump to particular sections, and so they never see the other links.
Most sites don't link every occurrence of a word or phrase to a particular page, so I'd say that's the de facto standard. That doesn't mean it couldn't work for your site, though.
Msg#: 3751114 posted 6:40 am on Oct 6, 2008 (gmt 0)
As ReceptionalAndy mentioned, linking to your page once with the keyword can do the trick. I don't see any benefit of linking to the same page with the same anchor text from a single page again and again. Getting links with the same anchor text from different pages can be helpful.
Also, using the same anchor text to link to your page might not be a good idea. Try and vary the anchor text for different incoming links.