For comparison, as of the most-recent difficulty adjustment, the total amount of hashing performed on the Bitcoin network globally is about 3.1 Thash/s. That T stands for the SI prefix tera meaning trillion. Thus the entire Bitcoin network is performing hashing work at the rate of 3,100,000,000,000 hashes per second.
Chrome will generally be the browser software that will return the highest hash/s number for most computer systems.
A top of the line $2,200+ mining rig with dual AMD Radeon 6990s and running the latest builds of specialized miner software will hash at approximately 1.44 Ghash/s (1,4400,000,000 hashes/s) and earn just under $30 USD per day at the present difficulty level and market exchange rate.
But go ahead. Give it a try. Mining for bitcoins will be one more thing you can draw a line through on your bucket list.