There is no webpage for the pebbles, no archive. You can subscribe to receive them via either email or an RSS feed. Maybe by actual post, at some point in the future too?
Grey Pebbles is strung together using bits of net glue. To make things fairly simple and lightweight (no Wordpress cheating here), TinyLetter speaks to Procmail which speaks to a customised version of this imap2RSS script. (Modified code will be available soon.) Finally, to get images embedded properly, I use Gmail's "Inbox" app to send emails. This is the only Android email client i've found so far which lets you insert images inline. Going via TinyLetter first also handles attached images and converts them into URLs nicely, rather than keeping them as encoded images.
This page is generated using Slimdown.
I can be found at email@example.com in the eventuality of any questions.