I use nl2br for the linebreaks. Commenting now takes you to the map page again and logging in directs you to your user page (best solution at the moment).
Since making a full-blown search function is way outside my league at the moment some recommendations on server-side filters for the listing would be nice. Since I write these things in the most ugly ways I will only implement things that are not easily done with the javascript filter.
Show only:
-maps/"mods"/speedmapping stuff
-rated x and above
-user rated x and above
PS: I know that I have to implement a fair algorithm to sort user ratings. But
http://www.ibm.com/developerworks/web/library/wa-bayes1/ really scares me though.