I'm in the 'come on over' camp here. I mean, I guess if a specific family was coming over unannounced every other day it would get to me and I would have to say something. But an occassional drop-by visit - I like it! Now, granted, I would expect them to be courteous and make it a quick visit if it looked like they caught us at a bad time (putting kids to bed, doing the taxes, or whatever), but if we're just hanging out or, even better, if I'm cleaning the house - COME ON OVER AND GIVE ME AN EXCUSE TO VISIT INSTEAD!
I guess maybe it's because my house was very much a 'go to' house as a kid and even into my young adulthood when I still lived with my parents. We never locked our door (I know - times were different) - but it was not unheard of for many, many friends to drop by and let themselves in at different times. I honestly don't want my kids' friends thinking they need to call to setup a 'playdate' every time they want to hang out - just ride your bike down the street and if my kids are in the yard - join right in. I like the informality of it. If someone calls and arranges a time - well, then I feel like the hosue needs to be cleaned first, and munchies and drinks arranged, etc. And, this just can't be done all the time. I like that it leads to more getting together. How many times have you said to someone that you really like but don't get to see often enough 'let's get together again soon'?? And often, it just doesn't happen because the appointment is never made and a 'good' time in both your schedules is hard to come by. But if that person happened to be in your area and dropped in....Well, sometimes it ends up being the best thing and the only way that get together is going to work out with any timeliness.
That said, having this type of feeling, I know there are lots of you who hate it. I have a friend and across-the-street neighbor who has often talked about not wanting neighbors in her yard chatting every day. She wants her space. I honestly try to honor that, but sometimes it is a tough call to make - as I don't know where that line is between 'good friend and neighbor' and 'you're stepping on my toes'.
If any of you is ever in my area - stop on in!!! All are welcome!!!