It is now dead easy to manage large lists just declare a group and add a filter. The input field created by the filter will produce ajax calls to update the liste. Example to filter contacts :

<div do='group'><r:filter/>
  <ul do='contacts where name like "[params:q]%" in site'>
    <li do='each'><r:link/> <r:show attr='c_phone'/></li>
  </ul>
</r:group>

See filter for details.