if you can't figure it out why not use a plugin such as :
http://wordpress.org/extend/plugins/gregs-threaded-comment-numbering/

my complaint would lie more towards the title being misleading. Unless i am missing something these functions will count the total number of comments... not number them individually the way you see at this site. i suspect that might be done in the callback fb_theme_comment, but we don't get to see it in the post..

This is WebDev talk..
And even worse.. all sites online are just copy-/pasting the same story without knowing what they say just to gain traffic..

Very sad there is not one site online that just tells us none web-dev's in Micky Mouse language how to get comment -counts or numbers next to each post. Nothing more nothing less we don't need fancy trackbacks and pings and all other seo stuff we just like to add something important to our comments without the use of a plugin that has 500 features + an extra stylesheet!

Maybe this code does it all but it doesn't show you where to past it..

I'm sure I'm coming into the discussion out-of-context, I was trying to patch the code into my existing template. The most perplexing issue was: Warning: call_user_func(fb_theme_comment) [function.call-user-func]: First argument is expected to be a valid callback in [snipped] /wp-includes/comment-template.php on line 1219

Looking for the solution landed me on the wp-basis-theme page, and I was able to snip out the needed function from there.

Thanks again.