Back in May I posted about some of the pages of Codex Sinaiticus held by the University of Leipzig being made available on-line. Recently, a cooperative project by the four institutions that own parts of the codex has put up a larger number of leaves from Leipzig and the British Library, including parts of I Chronicles, 2 Esdras and Lamentations, and all of Esther, Tobit, Jeremiah, Psalms (including Ps. 151), and the Gospel of Mark.
The pages are nicely photographed in color, with choices of views with standard light and "raking light," in which illumination is nearly parallel to the page. Even at the highest resolution the images are clear; a transcription is provided, and there's a frame for translations into your choice of English, German, Greek, and Russian, although in spot-checking the only passages for which I found translations were Psalms 1-35, and those only into English.
The first phase will end in November, 2008, and the implication is that after that more leaves will be made available.