Desktop sharing in Hoary...?

[Nicholas H.Tollervey]

Guys,

I need to do some remote development work with a colleage elsewhere in
the UK. I want him to be able to see at the very least my development
environment (probably emacs) and at best my desktop. I also want to talk
to him at the same time using Skype although I'd rather use a "free"
solution. I'm also on a LAN (DHCP ip address ranges in 192.168.*.*)
behind a firewall and on 512 ADSL.

We'll both be using Hoary for this.

The VoIP skype solution is a no-brainer. Its the "remote desktop" that
I'm puzzled by. VNC could be the right choice but how does my mate know
which IP address to point to with his client? Secondly, what VNC screen
do I have to set in the VNC server in order for him to see my "real"
desktop?

Alternatively, can anyone suggest a linux based desktop sharing
application? Googling for that search item only returns stuff to do with
(a client for a windows protocol) r-desktop or VNC related links that
don't answer my questions.

HELP?!

TIA

Nicholas