Is your intent to replace the HDD in your notebook with the SSD? If so, the answer is no, there would be no space for any sort of adapter inside your computer. Yo can check, however, to see if your notebook supports configurations with SATA HDDs.
If that is the case, you may just need to find the SATA connector and cables for your notebook and install them. I have a Dell that supports both IDE and SATA HDDs, the type used depends on the physical interface and cable installed.
The Latitude XT is a nice system and no, it does not support SATA devices (I thought it may previously). So, in order to install a SSD, you will need to find one with a PATA interface. You really don't have any other viable options. Sorry.
For the second one, it won't work. Look at it closely. It is intended to plug into a SATA port. Yours would need to be the other way around.
The DIY methods may work, but you could fry your Latitude XT if you make a mistake (like pinching the cable and grounding the system). One of the links on the first link looked promising (http://www.dealextreme.com/details.dx/sku.19736), but I doubt you have the space to mount in your Dell.