I don't collect links, but here are just a few that I like to visit from time to time:

"Hiking Links" by Henk Nouws helps you finding your next hiking destination. I like the searchable trail database:

The Hiking Page maintained by Ton de Maagt has many informations on hiking in Europe:

The Potomac Appalachian Trail Club operates a noncommercial Webserver with an remarkable amount of information:

The Backpacker has searchable databases of trails in USA

CyberHikes is partly dedicated to California and worth to visit:

Utsidan collects reports in Swedish and English language:

The Ultralight Backpacking Page: