to my knowledge perusing the intarwebz-- and my experience has corroborated this-- the local sims only pay attention to the laser harp (much easier to spell : ) at a Big Park. it's an actual qualification of lot. the problem is that if you also run seasons, it replaced the Big Park with a Festival Park... so it doesn't count as a Big Park for the entire time a festival is running. which, iirc, is six out of seven days.
so i had to create my own Big Park in isla paradiso. it isn't all that big or fancy, but it's got some stuff for sims to do, and there are always people around.
unfortunately, most of the worlds are pretty lousy for tips. the subways of the [late night city] are good, as are the venues of the [showtime city]. but the only public park with which i've ever had consistent success is the very very original vanilla city.
