As you may or may not be aware, Google recommends keeping the number of links on any given page to under 100. This recommendation can be found among Google’s webmaster guidelines under the Design and Content Guidelines section.

Google’s Matt Cutts took the opportunity to explain the reasoning behind this suggestion. He says that originally Google would only index 100kb of a page, and pages with larger amounts of links ran a higher risk of not being indexed entirely.

Google will now however index more than 100kb, but the recommendation remains, and the reason is user experience. The general thinking as Cutts presents it is that users don’t like pages with a lot of links.

He says that in some cases it makes sense to have over a hundred links. Don’t worry, Google does not automatically consider that spam. Still, he notes that such pages can be spammy, "especially if the links are hidden or keyword-stuffed."

Sidenote: While on the topic of linking, there is another interesting story about linking practices being threatened in this exclusive discussion between legal experts:

"If you end up with hundreds of links on a page, Google might choose not to follow or to index all those links," explains Cutts." At any rate, you’re dividing the PageRank of that page between hundreds of links, so each link is only going to pass along a minuscule amount of PageRank anyway. Users often dislike link-heavy pages too, so before you go overboard putting a ton of links on a page, ask yourself what the purpose of the page is and whether it works well for the user experience."

To me, it’s going to come down to personal judgment. Use links where they make sense and you’ll probably be fine on the user experience level. Linking for linking’s sake is probably where might start turning people off.