At first I thought commenting would be nice on my tumblog, I could never find a solution I liked.
But then I slowly realized that it defeats the purpose. I use tumblr as a quick way to share random things with lots of people, instead of cluttering up their Facebook feeds and IM windows with 20 shared items a day. I don't want to be managing comments as well. That's what every other account/service I have on the Internet is for.
I'm also attaching the Haloscan instructions. I won't take credit for the instructions. I got them from alicia @ http://alicia.tumblr.com, who helped me in getting the code on mine.
I'd have to agree with Zac -- it does defeat the purpose of a tumblelog, but I like to hack around, and Tumblr is a great place to experiment with code.
i did the haloscan option. and paid my $12 so it wouldn't have ads. :) i played around with it a bit and finally decided just to have a small comment graphic by the date on each entry. i wanted the commenting option to be there but also for it not to change the light tumblr feel.
I too, agree with Zac (though you didn't ask if you should use comments or not :-) I don't use comments so I can't help ya there. Good luck on finding something that works out for you. I think re-blogging is a great way to comment on someone's post.
I started using Disqus for commenting on my tumblr page and, I have to agree, it works great. It's very simple to get working correctly and it fits seamlessly into tumblr. You couldn't find a more effective way to add commenting to your tumblelog.
I respect people that don't want comments on their Tumblr. But I do want them.
I suppose seamless, integrated comments on the permalink page would be nice. But failing that it's not too bad to have them in a seperate popup - it keeps them out of the way. Haloscan does that nicely.
And of course now I have Haloscan I'm stuck with it, unless I want to lose all the comments people have made. Which would be a bit rude.