I recently purchased the Chomas Creations pen adapter so that I can write with my Silhouette Cameo and tried it for the first time today. It worked very well using a pink glitter pen to address an envelope.
Mikaela's 4th Birthday by tweedcurtain - Cards and Paper Crafts at Splitcoaststampers
I made a pop-up castle using a cut file from the online store for the inside of the card. You can see it here:
Mikaela's 4th Birthday Inner Pop Up by tweedcurtain - Cards and Paper Crafts at Splitcoaststampers
More info here: Tweedcurtain Productions: Cameo Castle and Chomas Inked Envelope