I've been working a lot with Google Docs Forms to capture data. Two features I've found valuable are embedding a form into a webpage, and having notifications sent when the form is filled out.
Google forms can be embedded as an iframe into a webpage. To find the iframe URL for your form, click on "more actions > Embed" from the form page. The form will display an iframe element with the URL to your form. The iframe URL can also be found via the form's results spreadsheet, in "Form > Embed Form in Webpage" You can embed that URL into a Google Site, Wordpress page, or any other website.
Forms (and any Google spreadsheet) can also send notifications when they've been submitted. From the results spreadsheet, go to "Tools > Notification rules". You can have the form send you an email when it is submitted, when a field changes, or if the collaboration options change. For high-traffic forms you can opt to send one email a day, or have an email sent for every response for forms that will only be used occasionally.
Andre