I skim a lot (bec. I'm usually reading at work), but I bookmark or save links to interesting posts & check in on those thru the day or the next day. Also, since I'm on the west coast & checking in later than most ppl (you'll prob. find this too), this is handy bec. I see posts that have a few comments already, those are the ones where conversations are happening.

That said, I don't often comment myself due to time or bec. when I do have time, I'm commuting & on my phone (agreed, terrible for posting/commenting! I just read). But it still lets me keep up :)