Congrats on your new M9. Put it to use and enjoy it.
Accessorizing ... I'm a bit of a minimalist by nature, I often buy stuff to try out and then don't use it. What i find I use:
- spare battery ($129 ... I buy oem)
- HP SDHC class 10 32G memory cards (two of them, about $30 each)
- half case ... I bought case from Luigi which was very nice, but I found that for how I like to use the camera, any kind of back flap is always in my way. I tried the Artisan & Artist ... that does the job right for me. A half case protects the body and provides me with a more secure grip, I like it more than the Thumbs Up or Thumbie, which seem to always get in my way. The case was $260.
- a 12 inch cable release and tripod adapter plate for use with my QR system (I don't use the M9 on a tripod very often, but occasionally it is very handy like when using the next gadget ...) Ten bucks or so for the release, $40 for the plate.
- a Skink pinhole pro kit ... pinhole and zone plate photography is fun and challenging, and the Skink kit is nicely worked out for $90.
- A bag to carry the camera and junk around in. I like the Billinghams, I like the Domkes, but what I use for the M9 most is either a Black Label Bag "Oskar' One Day Bag" Mark II (from Photovillage in New York, about $190 IIRC) or an A&A GCAM 1100 "Elliot's Everyday Bag" (very pretty and too fricking expensive, but I got it used from a friend for $150), depending on how much stuff I need to carry. (The Black Label Bag version of the Oskar's One Day Bag is a little bigger and has a couple of features I prefer.) Another bag I use to carry gear around with a lot is a cheap and small Lowepro Teraclime 100 fitted with the interior insert from the GCAM 1100 (that's $80 for the bag and $110 for the insert); it works a treat for a light kit.
You can read into the above that I have a Thumbie and a nice Luigi half case for sale. Drop me a note if you're interested.