Mine

ON *:TEXT:*:#:{ if (*$* iswm $2) { halt }
  if ($1 == !leet) || ($1 == l33t) || ($1 == 1337) { set %leets $2-
    %leets = $replace(%leets,1/4,¼)
    %leets = $replace(%leets,1/2,½)
    %leets = $replace(%leets,3/4,¾)
    %leets = $replace(%leets,AE,Æ)
    %leets = $replace(%leets,a,å)
    %leets = $replace(%leets,b,ß)
    %leets = $replace(%leets,c,©)
    %leets = $replace(%leets,d,Ð)
    %leets = $replace(%leets,e,ê)
    %leets = $replace(%leets,f,f)
    %leets = $replace(%leets,g,g)
    %leets = $replace(%leets,h,h)
    %leets = $replace(%leets,i,ï)
    %leets = $replace(%leets,j,j)
    %leets = $replace(%leets,k,K)
    %leets = $replace(%leets,l,£)
    %leets = $replace(%leets,m,m)
    %leets = $replace(%leets,n,ñ)
    %leets = $replace(%leets,o,ð)
    %leets = $replace(%leets,p,þ)
    %leets = $replace(%leets,q,q)
    %leets = $replace(%leets,r,®)
    %leets = $replace(%leets,s,§)
    %leets = $replace(%leets,t,+)
    %leets = $replace(%leets,u,ü)
    %leets = $replace(%leets,v,v)
    %leets = $replace(%leets,w,W)
    %leets = $replace(%leets,x,×)
    %leets = $replace(%leets,y,¥)
    %leets = $replace(%leets,z,z)
    %leets = $replace(%leets,?,¿)
    %leets = $replace(%leets,!,¡)
    msg $chan %leets
    unset %leets
  }
}