Pravit of The Nation has a story (with a great photo) on the red shirt rally. Key excerpt:

Red-shirt protesters, at least 100,000 strong, occupied Rajdamnoen Avenue Saturday and more kept flowing into the capital from all over the Kingdom Saturday night.
…
Arrivals quickly set up temporary shelters and cooked dinners in anticipation of a final bid to oust the Abhisit Vejjajiva administration and the old bureaucratic elite.

Makeshift toilets were being installed by the red shirts to supplement those provided by the Bangkok Metropolitan Administration, and many food stalls quickly sprang up.

As night fell some traded stories, while others went to listen to the main stage’s speakers on Phan Fah Bridge, which became a sea of red shirts.

“The line of cars was really long,” said one female red shirt to a male fellow protester. “Two hundred cars alone left Uttaradit,” the man added.

BP: On the cooking, see this Prachatai thread – it really is starting to look like the PAD mobilization efforts with logistics of water and food.