Don't have a lot, other than they're very handy for keeping an eye on everything in a single location. In my case, I have a growing RSS feed collection over on LJ, spanning a wide variety of blogging platforms--I'm not as familiar with the constraints over here on DW.

But if you have a smallish amount Tumblr content you'd like to keep following, you should be able to manage that through RSS.

I do have my LJ RSS feed link pinned on my blog here, if you're interested in seeing my posts go up daily instead of bunched up a couple times a week (and I think the videos actually come through in that case).