One thing clients always leave to the last minute and *love* striking off the time/budget for projects is the copy that, when used correctly, can really add character to your website and help form/define the personal attachment to it that its users feel.
This copy mainly exists as general system messages and automated emails. When using Content Management Systems like Joomla or Drupal, all of these messages are usually included with the software in default robot language - they don't read personally yet their purpose is very personal; to warn, inform and relate to the site user out of concern for their relationship. Such stock messages can usually be easily customised yet clients often feel [wrongly] that since the messages are already there, there's no point in drafting new ones.
I like many things about Vimeo, an online video upload/hosting/etc service, and one of them is the real-time communication they maintain when you upload a video - first off the website tracks the upload progress and gives you a realistic expected time of it being published, whilst allowing you to edit the video's description, add tags etc. Then, when the clip has been converted to flash video and is online, the site will send you an email notification (picture attached to this post).
Note: I think Vimeo's email notifications are definately under-designed and through using Times and Arial, with too many font sizes, they read a little roboty...But I love that they hit my inbox as soon as my videos are ready to watch with a thumbnail, description and link to the video!