I'd like to suggest taking the campaigns tool one step further, along with being able to have emails sent out automatically based on date, etc. that I've seen in other ideas, I'd like to be able to add leads/contacts to a drip campaign or multiple drip campaigns so they would get a series of emails at specific times. For example:

1. A lead comes in via web-to-lead.
2. automatically gets added to a campaign and an email gets sent out.
3. The campaign has 4 other emails associated with it. The time to send these out is based on the last email that was sent in the campaign. So you could have email 1 same day as lead came in, email 2, 1 week later, etc.
4. As people get added to the campaign, the process starts from the beginning for that person.
5. Once they've gone through the whole campaign, have the choice of any or all of the following, notifying a sales rep, being put into a different drip campaign, just putting them on completed campaign list.

If a lead was put in manually or via import, have the choice of adding them to drip campaign.

On the contact/lead form I envision a related list or something with all the drip campaigns they are associated to, and their status in each campaign.