Jonas

This will give you an advanced pagination to distribute your link-juice more evenly across your paginated paged. It also provides a better choice of navigation to the user to explore and find your content.
You can turn the pagination on/off separately for:
<ul>
<li>homepage</li>
<li>search results</li>
<li>category archives</li>
<li>date archives</li>
<li>tag archives</li>
<li>author archives</li>
</ul>
Or implement it directly into your theme using <code><?php the_wp_lopa('pages_below'); ?></code>.
You can also choose if you want it to be displayed before and/or after the loop content.
The plugin is currently available in English and German. If you want to help translate it, just write me an email. Help is much appreciated!
For more information visit the <a href="http://www.k308.de/labs/logarithmic-pagination" title="Logarithmic Pagination plugin page" rel="nofollow ugc">plugin website</a>.
<h4>Credits</h4>
This plugin is based on the idea found in the following (German) article by Nikolas Schmidt-Voigt: <a href="http://www.kawumba.de/webseitenstruktur-und-paginierung-fuer-seo/" title="Logarithmic Pagination plugin page" rel="nofollow ugc">Webseitenstruktur und Paginierung für SEO</a> & a 
<a href="http://stackoverflow.com/questions/7835752/how-to-do-page-navigation-for-many-many-pages-logarithmic-page-navigation" title="" rel="nofollow ugc">discussion</a> on stackoverflow.

Logarithmic Pagination

This plugin inserts pagination to your blog, archives and search results based on logarithmic calculation for a more evenly distributed link-juice.

scribu

Smart Archives Reloaded allows you to display a list of posts grouped by year and month. It also provides several interesting navigation elements.
Format list:
<ul>
<li>list = a list of posts grouped by month</li>
<li>block = a compact block of links to year and date archive pages</li>
<li>menu = a two-level menu with links to year and date archive pages</li>
<li>both = block + list (<a href="http://scribu.net/archive" rel="nofollow ugc">example</a>)</li>
<li>fancy = menu + list + JavaScript (<a href="http://www.conceptfusion.co.nz/archive" rel="nofollow ugc">example</a>)</li>
</ul>
No support
I do not offer support for this plugin, either free or paid.
Credits:
<ul>
<li><a href="http://justinblanton.com" rel="nofollow ugc">Justin Blanton</a>, for the original <a href="http://justinblanton.com/projects/smartarchives/" rel="nofollow ugc">Smart Archives</a> plugin</li>
<li><a href="http://www.conceptfusion.co.nz/" rel="nofollow ugc">Simon Pritchard</a>, for the fancy format</li>
</ul>
Links: <a href="http://scribu.net/wordpress/smart-archives-reloaded" rel="nofollow ugc">Plugin News</a> | <a href="http://scribu.net" rel="nofollow ugc">Author’s Site</a>

Smart Archives Reloaded

Easily display posts grouped by year and month, in one or more elegant formats

Logarithmic Pagination vs Smart Archives Reloaded