Send email to multiple users with sharepoint workflow

Environment: SP 3.0 + Office SharePoint Designer 2007

1. Create a new column in the list for the email recipients, say it's named EmailTo.

2. Go to the workflow designer, create a variable as type of string, say it's named MailRecipients.

3. Create two actions as below in workflow designer.

　　a) Store the EmailTo's value into MailRecipients.
　　b) Send an email, and set the recipient as variable MailRecipients.