iZoho is the mobile version of the Zoho Suite, developed specifically for the iPhone.
While you can access Zoho on your iPhone already, the iZoho release has been pared down and simplified for optimal use on the mobile device. Currently, you can access your documents, spreadsheets and presentations. Documents can be viewed and edited, while spreadsheets and presentations can only be viewed. You can create new documents as well.
Looks like there are plans to grant access to Zoho Applications on other mobile devices in the future, and there are definitely plans for new features to be released for iZoho with further development. Be sure to test it out once you get your hands on an iPhone, as Zoho itself hasn't gotten a chance to check it out for themselves.