Via Jim West's blog.
The Leipzig University Library has published their portion of Codex Sinaiticus on-line at www.e-manuscripts.org. One is required to first download an add-on for the web-browser, Microsoft's Silverlight. After installment and restarting the browser it is possible to view superb images of the manuscript.
There is also a press-release in Der Standard.
Now we are just waiting for the other three libraries who are holding parts of the manuscript to follow suit (St Catherine's, the British Library, and the Russian National Library. Read about the whole undertaking at the ITSEE website.