Buy old domain and redirect to new

Anyone try to buy a lot of domains with existing pr and do 301 redirect all of them into 1 new domain ? Any results ?

yes, it doesn't work

Take a look at the thread called "Penguin: My test results are in". jb gives the results of the experiments that he ran on his sites. He stated that the 301 works for about a week increasing SERPS for the new site, but the penalty is eventually translates over to the new domain.