well they would have to be a member then you just create a table like this:
CREATE TABLE IF NOT EXISTS favorites (
ID BIGINT NOT NULL auto_increment
MemID BIGINT NOT NULL,
URL VARCHAR(255) NOT NULL,
PgTtl VARCHAR(255) NOT NULL,
Stored TIMESTAMP NOT NULL,
LastAccessed TIMESTAMP NOT NULL,
PRIMARY KEY (ID),
INDEX MemID (MemID),
UNIQUE PgTtl (PgTtl),
INDEX Stored (Stored),
INDEX LastAccessed (LastAccessed)
)
Then just make a php script that will add entries to this and then redirect back to the referer.
Also put a little script on every page that will check if this user bookmarked this page and if so it will update their last accessed time.
This way the user can sort their links based on:
Title, When Bookmarked & Last Accessed.