My problem is the webapp I am working on is pinging the server at short interval so I have many lines coming in Network tab of Chrome developer tools.
Make use of negative text filters recently announced here (they should make it to the stable release in the near future if not already).
Chrome developer docs don't yet appear well updated but what is documented is available at
Chrome developer docs - Sorting and filtering
This feature was added in September 2012: https://code.google.com/p/chromium/issues/detail?id=117702#c4
Cmd/Ctr-F to filter in developer tools Network tab.
Firebug's Net panel currently only allows to sort the requests, it doesn't allow filtering besides by type (HTML, CSS, JS, XHR, Images, Flash and Media). Though there are two requests covering this: