For those to lazy to follow my link this is the important part:
" Takanen, chief technology officer for Codenomicon, advises you to wait for an official statement from the internet services you use (indicating that they have fixed the bug) and follow their guidelines.
Typically, that will involve things like changing your password. That is something you may have to do across many —services you use.
However, steps like that are useless until the security hole has been fixed for the affected services.
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Changing before the service is patched could expose the new password," said a spokesperson for Google, who also noted that passwords do not need to be changed for Google services because of its early implementation of a bug fix.
In the meantime, a number of sites have have been set up where you can check if the web services you're using are vulnerable, including this one, set up by Italian security researcher FilippoValsorda.
You might want to stay away from sites identified as "vulnerable" for now.
Security experts also recommend as a general rule that you use strong passwords that are different for different internet services and that you change them regularly.