I believe Time test is the bestest (wanted to make it Best test, fir plan change).
I mean Time tells you, who wants to keep in touch with you and who doesnt. Becos for acquaintances , or forgotten friends, we wouldnt prioritize our time.
So also as time goes, we analyze our friendship more objectively, and if we think the other person is not worth your time, then out the person is from memory frames and "time"frames..
Yeah, I am a bit cross with a friend who doesnt have time to talk / chat / meet. But I felt like writing more becos I just chatted with 2 friends of mine - One was my roomie in college days and other cubicle mate in the first 2 years of my first Job. I was soo unable to connect for more than 2 minutes with them. While there is this another friend(who was originally a friend's sister, but turned out to be closer than the original friend :P), I can connect with her pretty fast, and we keep chattering for hours together-even if late nights. I guess its a part of life..
I do beleive time can distinguish a friend for you. No matter after how long are you meeting/talking/chatting, you can still pick up the thread of communication. You dont look for topics to talk with a good friend, they just keep flowing..