Two small comments.
You set the font name, size and color every time something is written to the signature. This is not needed. You only need to set the font name, size or color if you want the following text in a different font, size or color then what you set it to earlier. There is one line that writes the word company, I guess you want to write the company name there.

I modified your code to reflect my comments.

 Code:
If InGroup("Domain Users")
	
	$objSysInfo = CreateObject("ADSystemInfo")
	$strUser = $objSysInfo.UserName
	$objUser = GetObject("LDAP://" + $strUser)
	 
	$strName = $objUser.FullName
	$strSN = $objUser.sn
	$strmobile = $objUser.mobile
	$strTitle = $objUser.Title
	$strDepartment = $objUser.Department
	$strCompany = $objUser.Company
	$strPhone = $objUser.telephoneNumber
	$strGivenName = $objUser.givenname
	$strMail = $objUser.mail
	$strFax = $objuser.facsimileTelephoneNumber
	$strWeb = $objUser.wWWHomePage
	 
	$objWord = CreateObject("Word.Application")
	 
	$objDoc = $objWord.Documents.Add()
	$objSelection = $objWord.Selection
	 
	$objEmailOptions = $objWord.EmailOptions
	$objSignatureObject = $objEmailOptions.EmailSignature
	$objSignatureEntries = $objSignatureObject.EmailSignatureEntries
	
	$objSelection.Font.Name = "Arial" 
	$objSelection.Font.Size = "12"
	$objSelection.Font.Color = "8421504"
	$objSelection.Font.Bold = "1"
	$objSelection.TypeText($strGivenName + " " + $strSN)
	
	$objSelection.Font.Bold = "0"
	$objSelection.TypeText(Chr(11))
	$objSelection.TypeText($strTitle)
	
	$objSelection.TypeText(Chr(11))
	$objSelection.TypeText(Chr(11))
	
	$objSelection.Font.Size = "14"
	$objSelection.TypeText($strCompany)
	$objSelection.TypeText(Chr(11))
	
	$objSelection.Font.Size = "7.5"
	$objSelection.TypeText("Design  Architecture  Masterplanning  Interiors  Graphics")
	$objSelection.TypeText(Chr(11))
	
	$objSelection.TypeText(Chr(11))
	
	$objSelection.Font.Size = "8"
	$objSelection.TypeText("Winner - Queen's Award for Enterprise: International Trade 2008")
	$objSelection.TypeText(Chr(11))
	$objSelection.TypeText(Chr(11))
	
	$objSelection.TypeText("T: " + $strPhone)
	$objSelection.TypeText(Chr(11))
	
	$objSelection.TypeText("F: " + $strfax)
	$objSelection.TypeText(Chr(11))
	$objSelection.TypeText(Chr(11))
	
	$objSelection.TypeText($strWeb)
	$objSelection.TypeText(Chr(11))
	$objSelection.TypeText(Chr(11))
	
	;adds the tree webding to the signature
	$objSelection.Font.Name = "Webdings"
	$objSelection.Font.Size = "18"
	$objSelection.Font.Color = "13421619"
	$objSelection.Font.Bold = "1"
	$objSelection.Font.Italic = "1"
	$objSelection.TypeText("P")
	
	
	$objSelection.Font.Name = "Arial"
	$objSelection.Font.Size = "8"
	$objSelection.Font.Color = "13421619"
	$objSelection.Font.Bold = "0"
	$objSelection.Font.Italic = "0"
	$objSelection.TypeText("   Please consider the environment - only print this e-mail if absolutely necessary")
	
	$objSelection = $objDoc.Range()
	 
	;this specifies what the signature is the be called and whether you want it to apply to forward and reply etc
	$objSignature = $objSignatureEntries.Add("default", $objSelection)
	$objSignatureObject.NewMessageSignature = "default"
	$objSignatureObject.ReplyMessageSignature = "default"
	 
	$objDoc.Saved = 1
	$objWord.Quit
EndIf
_________________________
Mart

- Chuck Norris once sold ebay to ebay on ebay.