WP Archive-Sitemap Generator plugin generates simple Archives/Sitemap based on your sites/blogs posts and pages. This is not another XML sitemap plugin, but rather a nice sitemap generator.
Download link: http://wordpress.org/extend/plugins/wp-archive-sitemap-generator/
Features:
1) Admin panel option (Settings->Archive-Sitemap) available.
2) Very easy to use. Just add <!--wp-archive-sitemap-generator--> to page/post under HTML section.
3) Generates Pages and Posts archive-sitemap.
4) Post sorting option available.
5) Page archive option available.
6) Page Navigation option added for posts on sitemap (in v0.9.7).
7) User can specify number of posts/page (in v0.9.9).
8) More features in next releases, please stay tuned.