There's two significant features I've been wishing for in my beloved newsreader, NetNewsWire, and the emergence of this cool little ListMixer app will suffice as the prodding needed to toss them out to Brent and the boys upstairs.

1. Per-feed expirations

I'd love a little drop-down menu on the "New Subscription" window (that's also echoed as a section in the feed's "Info for..." window) that lets me select how long I want to subscribe to the feed. It might be pre-popped with, say, 3 months, but the options I'd include are (1 day | 1 week | 2 weeks | 1 month | 3 months | 6 months | 1 year | Forever). "But why?" you wonder aloud, "these RSS feeds, they are so wonderful!"

Well, one of the reasons I ended up deleting all my RSS feeds last month was the fact that my collection had become a disorganized travesty consisting largely of things I'd stopped reading, packages that had been delivered weeks ago, and comment threads that hadn't seen a new addition in months. Noise, noise, noise, and it's all down to me to delete the junk one feed at the time. Screw that. Reset.

I've found an increasing number of my feeds are, by their nature, ephemeral, in that they will lose any value to me within a very short period of time. FedEx deliveries are the canonical example. What in this world could possibly seem more important before it happens, but could matter less once it's passed?

Letting me establish the life of a feed when I add it, but then giving me a cool interface to decide if I really want to delete it would be very cool, and it could come in the way of...

2. Smarter Dinosaurs

NetNewsWire has an unobtrusive but super-helpful little section called "Dinosaurs" ("Windows > Dinosaurs") which lets you display any feeds that haven't seen any activity over a period of time that you choose. It's a really neat way to weed out the old cruft, but it is sort of tucked away and not particularly fancy. I'd be surprised if most NNW users even knew it was there (let alone what it was for).

I'd love to see the Dinosaurs get the following education (and consequent managerial promotions):

• Every week or so, Dinosaurs pops up to do a little check-in with me
• It alerts me to any feeds that haven't "done anything" over my chosen period (I'd choose "one month")
• It shows me any feeds that appear to be broken or abandoned (404, etc.)
• It shows me all the feeds that have "expired" (per my instructions) since the last "check-in" and gives me the chance to resuscitate them with the same or a new expiration window
• It warns me of the feeds that are going to expire over the next period and lets me pre-emptively "renew" them
• It provides a nifty, whizzy interface for doing all this, including the ability to change the expiration date, per-feed in the Dinosaur Warn-i-nator.

Do-able? Appealing? Are there Mac or web-based reader apps out there that already do this in some form or fashion?

I was all sad and lonely the first few days that I had gone feedless, eventually adding back Andy's links and recent comments on my Flickr photos, but I have to say: I don't think I miss RSS stimulation enough to be willing to overload myself again. It's just not worth it.

But, if the tools matured, just a little, and I knew I could add new feeds without risking a deafening level of noise in a month, I think I'd be more adventurous.

As more of our stuff shunts over to RSS -- and so much of it can and should -- I think there's room for market leadership for the folks who can get these reader features right and help save our poor collective attention from further XML-based erosion.