I am new to carrying and just got a XD that has trigger and grip safety but is single action. I was nervous about carying this with one in the chamber since it is cocked when you rack the slide and no hammer ( I know this was redundant for many of you). However, I took some advice I read on this forum somewhere and cocked the pistol on an empty chamber and carried it for 2 weeks. One week of which was during vacation so it got carried under many circumstances, getting in/out of car, manuevering through restaraunts, lobbies and stores as well. It NEVER discharged during that 'test' so I now carry it 'cocked and loaded' and trust the safety features of the weapon, within the safe operating limits.
Thanks to everyone here that helped me to get over my nervousness. I now can carry confidently in the most effective manner, ready for work.