This snippet saves any links that starts with http://. It will also shows a random link when the !rlink command is used.

Update:
Wont save links more then once. (Doesnt matter wich nickname has applied it!)
Added !lastlink
Added Floodcontrol
Added an $iif identifier for the usage of @ public and !. private commands.

Example:

Nick: http://google.com
Bot: (echo) Links saved by Nick | Written http://google.com ( $+ By Nick $+ ) in links.txt

Nick: !rlink
Bot: Here is your random link: http://hawkee.com (By Bielie993)

Nick: !lastlink
Bot: This is the last link that has been saved: http://google.com (By Nick)

Check the printscreen for an example!!!!!!

on *:TEXT:*:#:{
  if ($isurl($1-) == $true) { 
    if ($linkcheck($wildtok($1-,*http://*.*,1,32)) == $true) { /echo Skipping the link since its already on the 4links.txt 1file! | return }
    else {
      /echo Link: ( $+ $wildtok($1-,*http://*.*,1,32) $+ ) saved by4 $nick | write links.txt $wildtok($1-,*http://*.*,1,32) ( $+ By4 $nick $+ 1) | set %lastlink $wildtok($1-,*http://*.*,1,32) ( $+ By4 $nick $+ 1) 
    }
  }
  if ($1 == !rlink) || ($1 == .rlink) || ($1 == @rlink) { $iif($left($1,1) == @,/msg #,/notice $nick) Here is your random link: $linkss | .ignore -u2 $nick }
  if ($1 == !lastlink) || ($1 == .lastlink) || ($1 == @lastlink) { $iif($left($1,1) == @,/msg #,/notice $nick) This is the last link that has been saved: %lastlink | .ignore -u2 $nick }
}

alias linkss { 
  if (!$read(links.txt)) { return Nothing Found }
  else { return $read(links.txt) }
}

alias linkcheck {
  if ($read(links.txt,nw,$+(*,$1-,*)) != $null) { return $true }
  else { return $false }
}

alias isurl return $iif($regex($1-,/\b(?:(?:htt|ft)ps?://(?:www|ftp\.)?|www|ftp\.).*(?:\.[a-z]{2,4})(?::\d+)?(?:/\w+(?:/\w*/*)*|(?:\.[a-z]{2,4})|\?\S*)*\b/gi),$iif($prop,$regml($v1),$true))