I implemented "validateaddress" in svn r169:
$ ./bitcoind validateaddress '1P3rpbSybuGgeL1bRwCJFWbn4yBjRNQrbY'
{
"isvalid" : true,
"address" : "1P3rpbSybuGgeL1bRwCJFWbn4yBjRNQrbY",
"ismine" : true
}
$ ./bitcoind validateaddress '1111111111111111111114oLvT2'
{
"isvalid" : true,
"address" : "1111111111111111111114oLvT2",
"ismine" : false
}
$ ./bitcoind validateaddress 'mwFzbfqePwXUyT28e1kFVVh48uMHDsRzbi'
{
"isvalid" : false
}
No address version number; that wasn't trivial to do, so I didn't do it.