you can register for free trials online to get an online fix (full line-up not available).
google for "XM online 30 day trial" and you'll see a few links (usually from GM, chevy or other manufacturer's websites) with month-long promos.
you'll need a new address every month. i've been doing this for the past 18 months using a 30-day code from an old (!) oprah magazine.
be sure to go to settings and change to high-bandwidth (64k) streaming because by default it's 32k and sounds terrible.
i swear this might come in handy when you entertain over the holidays coz it's ad-free! the x'mas tunes are also just right.
p/s: yes, i've been offline for so long due to work commitments! i'll be back with more rubbish later this month.