an improved version that will allow a nick to make 2 requests before blocking for 5 seconds
Code:
on *:text:!bartender *:#:{
  if ($eval($+(%,floodstop.,$nick),2) > 1) { return }
  else {
    if ($eval($+(%,floodstop.,$nick),2) == $null) {
      set [color:red]-u5[/color] %floodstop. $+ $nick 1
    }
    else { 
      set [color:red]-u5[/color] %floodstop. $+ $nick 2
    }
    :bartender
    if ($2 == buy) {
      describe $chan serves a refreshing $4- to $3 $+ . On $nick $+ s tab.
    }
    else {
      describe $chan serves $nick a refreshing $2- $+ . 
    }
  }
}


Change the -u5 to a higher number if you need to