Can anyone recommend a half decent script that operates a links section of a web site. Looking for something similar to this...

Allow visitors to add their link via online form
Some sort of spam control (either image or numeric code entering)
Allow links to be placed into categories
Shows the links and cetegories and if possible allows person to search through links
NO absolutley necessary but it woul dbe nice also if it requires a reciprocal link that it checks for.
Also an admin page to administer everything