Do you need to check how your website look on combination of browsers under different operating systems? Try entering the URL on the first page of the browsershots website.
Just choose the browsers you want to test under each operating system (no MAC OS available) the browsershots service will produce a series of images which area available online for 30 minutes, but that you can download and save for a more careful analysis.

Using telnet in Cygwin is very easy, but most people does not realize that it is not installed by default, therefore when you try to run telnet on a Cygwin shell you are instantly returned to the prompt. This happens because Cygwin finds the Microsoft telnet installed in your windows box and runs it; but this won't work in a Cygwin shell. To find out if this is the source of your problems type:

    $ which telnet
    /cygdrive/c/WINDOWS/system32/telnet