Not everyone can use a mouse well. For those who can't a keyboard might be a better option.
It is possible to jump through the links on a page using tab. Where there are lots of links this can be annoying or confusing. Try tabbing on this page. Often you cannot even see which link is active. Once the correct link is highlighted the user presses Enter to follow the link.
You can help them by making sure the tab order of links is intuitive. Or you could also make important links come first. If you want to you do it by adding a tabindex attribute to the link. Open links.html and change the first link in the second list from this:
<li><a href="textonly.html" tabindex="1">text</a></li>
The first time you press tab on your keyboard the highlighted link should now be this one. On most Western sites it is probably best to have the tab indexes from top left to bottom right but maybe for the important links only.
It is also possible for the Web author to add keyboard shortcuts to links. The user will not know these are there unless you tell them and so on a general Web site you might not want to bother. However, on a site they use a lot (like an online database used by an employee) it might be very helpful.
All you do is add an accesskey attribute to the last link in links.html (the koala one):
<p><a href="linksinternal.html#loc" accesskey="k">Where koalas live</a></p>
Now the user presses Alt-Shift-k to follow the link.