idea for a much needed application

I remember a while ago reading about tim burners-lee and how his
vision of the WorldWideWeb as a medium where all can freely and easily
publish information has not materialized properly, and i felt it so
strongly over the past week when trying to look at options for hosting
a website. Hosts are either expensive or limit you in terms of what
languages, modules, applications, and OSs you can use. They also limit
you in terms of space, bandwidth used per period, number of executions
of CGIs... etc. Some of those who give good deals, seem difficult to
trust with either your credit card number or your content.

I wish i can just use my own computer, with whatever technologies I
choose, keeping my content that i build up over time safe here on my
own machine, but unless you have a broadband connection this is not
possible. It may be possible using a dynamic DNS provider, but then
again either they add cost, end up with an ugly URL, and, most
importantly, there's no way for others to know when you get online. So
here comes the idea that occured to me, and i post it here to ask if
you know of an application that already provides this functionality,
then please tell me what it is, or if you think it is worth doing on
an open source basis, or even proprietary, in which case i invite
anyone to do so, or if you think it's a completely stupid and
impossible idea, then perhaps you can please tell me why.

You probably guessed if you read as far as the second paragraph that
what i'm thinking about is an application functionality that enables
instant messaging to provide the dynamic DNS functionality. So instead
of giving others a URL I can just give them an IM username they can
add to their client, and when i go online, through my humble dial-up
connection that changes IP whenever i log in, they'll be aware of my
presence, and be able to connect to a server i host on my machine.

It sounds like a simple thing; IM presence, automatic IP query of my
username, click on my username and or use a contextual menu option or
whatever and a browser launches to go to the site i'm hosting on my
machine. Perhaps it can use existing open-source platforms, such as
jabber or gnutella, or as an add-on to existing open-source
applications/clients. Basically what i'm suggesting is a little tool
to enable a server such as apache to join the whole IM/p2p thing and
have "presence". The more automated it is, and the easier it is, the
better. I think such a functionality will be especially useful for
certain uses, in my case it will be hosting a wiki, as i leave my
machine online a lot through my dial-up, can't predict the number of
executions of CGI or the amount of space needed, wish to be free to
use whatever wiki application is best for my needs and in whatever
language regardless of what a host will support, and do not wish to
pay a monthly fee, extra charges, setup fee or a domain registration.
Perhaps there can be other areas where it is useful, and i'm sure
there are other areas where it will not be suitable. Perhaps there can
also be a simple way to enable a page hosted in such a way to be
submitted to search engines, i haven't thought about that yet, but
tell me if u see any.

What do you think? already done, worth doing, stupid, or impossible?
(p.s. please also let me know if there are other newsgroup to which
posting this will be a good idea)