Information can be measured in terms of bits, but mass cannot. However, the mass of the *visible* universe can be estimated by direct observation, and an early estimate was roughly 10^53 kg (first link, based on an observable radius of 18 billion light-years and a critical density of 6 x 10^-27 kg/m^3). Using more recent data (second link, observable radius 13.7 billion light-years and critical density 9.9 x 10^-30 g/cm^3 or about 10^-26 kg/m^3), the mass of the observable universe is closer to 7.4 x 10^52 kg. However, according to current theory, less than 5% of that mass is in the form of ordinary matter (roughly 1 proton per 4 cubic meters); about 23% is dark matter, which can be detected through its gravitational effects, and the remainder consists of "dark energy," which powers the ongoing acceleration of the expansion of the universe.

With regard to the information content of the universe, estimates range from near zero (third link is the article referenced in the fourth link) to 10^91 bits (fifth link) to 10^120 bits (sixth link), with an estimate of 10^100 bits of entropy thrown in for good measure (seventh link).

However, the observable universe is only a tiny fraction of the entire universe, so the above figures need to be multiplied by an unknown but probably extremely large factor to apply to the *entire* universe.
Source(s):
http://www.cs.umass.edu/~immerman/stanford/universe.html
http://map.gsfc.nasa.gov/universe/uni_matter.html
http://citeseer.ist.psu.edu/cache/papers/cs/25800/http:zSzzSzwww.ufpel.tche...
http://www.advancedphysics.org/forum/showthread.php?t=4402
http://davidgalbraith.org/information-equation-of-state-for-universe/
http://focus.aps.org/story/v9/st27
http://www.sufizmveinsan.com/fizik/holographic.html
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970630c.html

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