Keyword filtering

Agreed.  We think this is a good idea too.  That said, there's some work to implement it.  We don't have time right now.  That said, I think I could squeeze a small piece of this into the code in my spare time and that's "Mark thread as unread".  I find I need this one a lot.  If I look at a thread once and then find I'm not interested in it, but people still reply in it, I still see the "new unread items" icon.  By being able to mark a thread as unread then it will look like all the other threads I haven't look at yet.  This would also give you a sort of "fake" ignore in that it would just have unread items like all the other threads you haven't looked at yet.  Ignore by keyword is definitely cool, just doubt we'll have time for it anytime soon.

P.S. We're slowly working towards getting our source code ready to ship out to CodePlex so if you wanted to add it (when we get it out there) feel free and we just might push it back into the site. 

I hear you.  Just telling you which one's easier and will probably get done.    You and I probably read the coffeehouse differently.  For me, most threads are unread and a few are read so only the "partially read" threads catch my eye.  Are most of the threads read for you so the unread and partially read threads stick out to you as something you should read?

Mark all as read is actually a hard one with the way we're currently built.  I can go into detail if you'd like, but without some rearchitecting "Mark all as read" would probably slow things down quite a bit.

I implemented it, so you can mock me.  But not really.  I built it for what we needed then.  I thought about "Mark all as read" when I built it, but it was going to be a lot more work to enable that.  I built it to cover the highest percentage of situations for the lowest cost.

We don't use cookies for anything because they don't follow you.  So if you use a different machine you've lost your read/unread status.

Not that bad at first.  Until everyone's been using the feature for a year and then we're back to the same problem. 

There actually IS a solution to the problem.  Well, sort of, anyway, but it involves quite a bit of work.  Basically, we'd have to take the total number of posts and the total number of threads you've marked as read and see if you have more than half read or more than half unread and then flip the meaning (for you) in our database.  Then mark all as read actually becomes a performance GAIN because only records for posts you've marked as unread will be in there.  I did build it in a way that makes it so we don't have to rewrite everything to enable this, but it's still a fair bit of work (and testing).

How to efficiently deal with large lists of data was actually an interview question I got here at Microsoft (the 2nd [out of 3] time I interviewed).  Fun stuff.

I was actually thinking the same thing when I replied to you.  That would make things interesting.  I sort of doubt it would work though unless you're logged in with the same user (to a domain).  I would guess the cookies are generated by user on the machine so they can't be used anywhere else.  Just a guess though.

Ha.    He could build his own on another site (or app) I suppose. 

With HTML 5 having offline storage that might also be a good alternative, but only if something like Live Mesh could sync them across devices for you.  Otherwise, you'd have the same problem as with cookies.