Unless you watch the charts 24/7, it may be helpful to set up price notifications.

Don't miss the bargain - get notified by SMS, e-mail or Jabber whenever the price changes or reaches a certain value.

And even if you track the prices 24/7 you may still want your Jabber client to tell you about every single price change on major exchanges.

All this is possible at https://bitcoinnotify.com - hopefully you will find it useful.