You can add rel="nofollow" in any links you don't want a bot to crawl. In this case, you can apply that tag to all your links and google won't follow them off your main page.
http://en.wikipedia.org/wiki/Nofollow
EDIT for clarification:
Page "A" is for widgets. You want this page to be returned for searches regarding widgets; on this page is a "related searches" section which links to Other Widgets. On all the anchor tags on page "A" which link to pages "B" and "C" (the related searches for Other Widgets), you'll put a rel="nofollow" tag. This will prevent Google from hitting page A and then following your "related searches" links off to pages "B" and "C".
This will NOT prevent pages "B" and "C" from being indexed on their own, it just prevents them from getting pulled in from page "A".
EDIT#2:
rel="nofollow" tells bots you don't want them to follow the link to the second page. Regardless of the anchor text on a link from A->B, if you've nofollowed it the bot won't "flow" pagerank to the linked-to page and should not follow the link to page "B" to index it due to that tag on the anchor. Note that this is not foolproof: Yahoo and other SE's may not treat nofollow like Google....so your best bet is to make sure that each page is strongly on-page-SEO'd such that it gets included in the index for the term you want it to be included for. Hope this helps...but like much of the SEO world there are few hard-and-fast rules which apply universally.