I keep my N900 with me all the time and use it to take a lot of photos, so accesibility is important to me.

Just bough a CP-231 leather case from BMC Digital - Genuine Nokia for £11.99 inc delivery. Arrived the next day!

Looks good, doesn't add any bulk so it still fits the pocket. N900 slips in and out easily and quickly. I use a screen protector from uk-tek - clearer than the excellent Proporta alternative and a lot cheaper - I can afford to replace them every couple of weeks or so if needed. Gives less feel than the Proporta when scrolling with finger or stylus and does show fingerprints more, though.

I carry a couple of spare fully charged genuine batteries just in case in a converted leather credit-card holder, but have never had to swap batteries yet as I go fully offline when walking for some peace & quiet!.