So, you want to run Google Chrome (or Chromium), but you're annoyed by incomplete support for SSL client certificate authentication. As of Chrome 6, this is mostly complete, with the exception of some GUI on the Linux side. If you are running a previous version, you should update, as there were a number of issues (specifically a certificate filtering bug on Mac OS X, and some missing UI) that affect usage at MIT.
While not strictly necessary for client authentication, most MIT users will want to add the MIT CA to the list of trusted CAs. You may also want the CSAIL CA (specifically, the Master CA). On Windows or Mac OS X, downloading the file and opening it should be sufficient. If you've already configured this for Internet Explorer or Safari, respectively, you may skip this step; Chromium uses the system certificate store.
On Linux, however, Mozilla Firefox uses a private certificate store instead of the system NSS one. There is no system interface for adding certificates, and Chromium has not implemented certificate manager on Linux yet. You may star Chromium bug #19991 to be informed of progress. In the meantime, you may use the NSS command-line tools to manage your certificates. If you're running Ubuntu or Debian, install the package libnss3-tools. To trust the MIT CA for SSL, download the file and run
certutil -d sql:$HOME/.pki/nssdb -A -t "C,," -n "MIT CA" -i path/to/mitca.crt
For more information, visit Google's page on Linux certificate management and Mozilla's documentation on certutil.
As of Chrome 6, the standard workflows should work without workarounds. Visit the usual usual web interface and follow the instructions to install certs normally. You can check your work with this demo page. If everything is working, it should welcome you by name, and tell you that a certificate for your username is installed.
While NSS does allow you to configure your certificate store to use smart cards or protected by a password, Chromium does not support this yet. Star bug #42073 to receive updates.