Several reputable manufacturers make pod based espresso machines. The Pod Merchant sells a wide variety of coffee pods from many different sources (nearly all Italian). I would have to agree with the post above: because they are ground, then packaged and shipped, and often sit on the shelf for a while, they tend to be stale. The time lag is just too long for any chance of freshness. They ARE convenient at work, and make cleanup a breeze. One possible option is (I really hate to say this)... Charbucks espresso pods. They are dated, and since they are not being shipped overseas, have a better chance at being less stale.
Of course, if you are located in Europe, you might find an Italian brand that is dated and shipped only a short distance, giving it a fighting chance of freshness.
I'm new here and this is my first post but I do have to comment on this post. Although I am a loyal Keurig Fan and always will be I do own a Senseo machine and find that if you put the pods in the freezer when not in use, it prevents them from getting that stale old taste. In my experience, ground coffee only becomes stale after it has been exposed to air....I could be wrong though so please don't quote that as fact =] If you have any question about pod machines let me know, I did my research on those babies before I got one 8)