Go to the SharePoint page that you require the redirect to take place.
Choose Site Actions, Edit Page.
SharePoint Edit Page
Add a new XML Web Part to the page.
Add Web Part
Choose Edit, Modify Shared Web Part.
Modify Shared Web Part
Select the XML Editor Button.
XML Editor
Input the following XML:
<meta http-equiv="refresh" content="0"; url="http://www.google.couk<URL>">
Replace http://www.google.co.uk with the url of the site/page you wish to redirect to.
Choose OK to close the Editor.
Expand Layout and choose Hidden.
Hidden Web Part
Click OK, then Exit Edit Mode.