What constitutes good manners when blogging?

Personally I like to leave comments on friends' blogs even if I have very little to say on the subject of the moment just as an indication that I am still reading and still interested, but I have to admit that this can lead to a lot of waffle and occasional accusations of trying to take over.

As a recipient I like to know who has visited, and appreciate the sort of comment which may in reality amount to no more than "Still here, Lissa". I also like to answer comments even if it is only "Thank you for your comment", and will usually visit the commenter's blog at least once.

And what about friends made while blogging? If you find yourself in the area do you make any attempt to meet them outside the virtual world of Blogland? I can imagine that if Sunday and the right part of Scotland coincided I might visit the public persona of Rev Ruth or Rev Kristan since I would want to go to church anyway, but surely attempting to visit the private people would be an intrusion, wouldn't it? On the other hand I think that I might respond quite warmly to an email from a long time blogging acquaintance saying that they were going to be in the area.

What do other people think?