Shortly: Vote for Zimbra in the Suggestion list of your cpanel.
I'm going to be buying an iPhone, but realized that it would be a pretty crippled device coupled with my Google-based email/calendar/everything. In my searching for an alternative--a service that integrates and syncs contacts and calendar via iSync or an Outlook connector, offers IMAP email, fully functional attractive webmail (not SquirrelMail!). I realized nothing out there offers these features except Zimbra, which seems like an amazing service--a complete Exchange-killer based on open standards.
I would love to use Zimbra in conjunction with my current account (not installable), but DH said they don't have plans to offer it unless it gets voted up on Suggestions.
So, I'm writing to see if other DH users might want Zimbra, particularly the Network Edition, and to make sure they understand it's much more than a simple webmail program--that it could offer some incredible PIM and collaboration functionality, with IM, file-sharing, and a cool AJAX interface. If so you really should vote for it in your panel, where you'll find a two-year old request.