parallel ssh tool roundup

So I'm in the market for a good "parallel" ssh tool.  Basically, I want to ssh and type some commands like I always do except that instead of one command output, I want the command to be run on a bunch of machines and I want responses from each.  I've used things like mpiexec in the past, but I was hoping for something more ad-hoc.  I just want to specify hosts on the command line (with no prior setup).  I really don't even want to required ssh keys or having the same password if I can avoid it.  Like I said, just ssh as usual, run some commands, get multiple results.

Anyway, these are the tools I've come across (in no particular order).  I'll outline what I regard as the advantages and disadvantages of each below.

1. pdsh - "a high-performance, parallel remote shell utility" from Lawrence Livermore National Laboratory
2. pssh an implementation of some parallel ssh tools in python
3. dsh - dancer's / distributed shell
4. pydsh - a python version of dancer's shell
5. clusterssh - "a tool for making the same change on multiple servers"
6. mussh - "a shell script ... to execute a command or script over ssh on multiple hosts"
7. sshpt - "SSH Power Tool (sshpt) enables you to execute commands and upload files to many servers simultaneously via SSH"
8. multixterm - part of the expect project
9. clusterit - "a collection of clustering tools, to turn your ordinary everyday pile of UNIX workstations into a speedy parallel beast"
10. dish - "The diligence shell 'dish' executes commands via ssh/rsh/telnet/mysql simultaneously on several systems"