Here is a little code sample, that I run into the other day. The actual URL is here, but since the original site is now closed, I thought that I could save this posting on my blog as well.
If anybody running CodeGear RAD Studio 2007 ever wishes to play with GUID's then this function is a real must have, All credit goes to the original poster.
interface function GUIDString: String; implementation uses ActiveX; function GUIDString: String; var Guid: TGUID; wsGuid: WideString; begin Result := ''; { create the 128 bit integer } if CoCreateGuid(Guid) = S_OK then begin { create a buffer of suitable size } SetLength(wsGuid, 80); { convert the 128 bit integer into a Unicode string } if StringFromGUID2(Guid, POleStr(wsGuid), 80) > 0 then { convert the Unicode to a String for output } Result := OleStrToString(PWideChar(wsGuid)); end; { if CoCreateGuid ... } end;