Richard MacManus has a guide to moving comments to PyCS, although he ended up doing it in a really difficult way, so I wouldn't recommend that anybody follow his instructions!
Try this instead:
1. Fill out the form.
2. Ask me to import your comments.
3. Open Radio and go to the comments preferences page.
4. Uncheck the box that says "Check this box to use comments".
5. Edit your templates and put in the bits that the form (see #1) tells you about. Put the <script src> stuff in your home page template and the comment link stuff in your item template. Put it after the <%commentLink%> and <%trackbackLink%> bits. Radio needs those if you want to go back to using the UserLand server later on.
6. Re-render everything - right click on the Radio icon in the system tray and select "Open Radio". Now click Radio > Publish > Entire Website and wait for a bit.
Now your comments should be working ;)
This way doesn't require you to edit any of Radio's source code, and won't screw up in future if the Radio developers decide to change some of the code you would have changed. My apologies to Richard, who ended up doing way more work than necessary because I didn't figure out this method in time.
[Second p0st].

Hey, this rocks. blo.gs has a feature whereby you can get it to ping you when it gets a ping. You tell it about your server with an XML-RPC call, and it'll then notify you when anybody updates, either by calling an XML-RPC method or POSTing some data to a page on your site.

In Python, you can get it to call you with XML-RPC (calling the function weblogUpdates.cloudPing) like this:

#!/usr/local/bin/python

import xmlrpclib
print xmlrpclib.Server('http://ping.blo.gs/').weblogUpdates.registerCloud(
    'http://my.server.com/RPC2',
    'xml-rpc',
    'weblogUpdates.cloudPing',
    'my random token',
    )

(Replace my.server.com with your server name and my random token with some text of your choice).

This code will print out a number. That's the number of hours (25 for me) for which it'll retain your server details. After that (well, before that) you have to call it again if you want to stay connected.

So, anyway, I had just made the Topic Exchange support the Weblogs.Com API so you could put http://topicexchange.com/RPC2 in your Movable Type ping list and connect to it directly, but then I found out about this blo.gs cloud thing, so you don't need to ping the Topic Exchange -- just ping blo.gs and the ITE will hear about it a few seconds later. Nice!

What this means is that the Topic Exchange now has a nice little weblog updates page. It's showing 1694 pings right now - wow.

[Second p0st]