What's the best way to stay in a conversation on Hacker News once you've commented?

There's not really a good way. You just check back every so often, and even then, there's not a good way to view the comments that have been newly added. This has been discussed here before, but HN deliberately tries to keep things simple, so I wouldn't bet on this feature being added anytime soon.

Just a messy Ruby-based example I threw together. Works for me.

  require 'rubygems'
  require 'open-uri'
  require 'hpricot'
  
  username = 'petercooper'
  uri = 'http://news.ycombinator.com/threads?id=' + username
  doc = Hpricot(open(uri))
  
  puts %{<?xml version="1.0" encoding="utf-8" ?>
  <rss version="2.0">
  <channel>
  <title>Hacker News responses to #{username}</title>
  <link>#{uri}</link>}
  
  (doc/'td td table').each do |post|
    content = post.inner_html
    next if content =~ />#{username}</       # skip if we posted it
    next unless post.inner_html =~ /vote/    # skip if it's not a post
    id = content[/\_(\d+)/,1]
    comment_text = (post/'.comment').first.inner_text
    commenter = content[/user\?id=(\w+)/,1]
    puts %{  <item>\n    <title>Comment from #{commenter}</title>}
    puts %{    <link>http://news.ycombinator.com/item?id=#{id}</link>}
    puts %{    <description>#{comment_text}</description>\n  </item>}
  end
  
  puts %{</channel></rss>}

With just adding a shebang line and a content-type header line, it works no problems on Dreamhost as a CGI script. Example: http://bigbold.dreamhosters.com/hnc.cgi

Anyway, thanks for giving me the idea. I'm using that now myself.. lol.

http://SeeURLater.com

You add a bookmarklet to your browser bookmarks toolbar, then whenever you're on a page that you want to remember to revisit later, you use the bookmarklet which fires up a little popup window, delicious style, that lets you save the URL. Each night you get one email message with all the links you added the previous day, reminding you to revisit them. No links added? No email the next day.

It's stupid simple, and very minimalist right now, but it's been working for me, and you're all welcome to use it. =-)

It's a shame there's no way to visually identify new comments, though. When I post up an article and I'm interested in all the comments, after it goes past 50 or so it becomes very hard to track new comments.