when at home, or the office and i'm connected to wifi, i noticed that after i swipe to "wake" the phone back up, the wifi meter is gone and 3G is what appears, after a few seconds, the wifi icon comes back, and 3G dissapears. if i'm not actively using wifi, does the phone somehow shut this feature off until i "wake" the phone back on?
I believe it works the same as your computer wifi. if your phone is sleeping then it is not actively connected via wifi. unlike your computer, though, i have noticed that you will still get updates to mail and such but my guess would be that it is done over the cell network, kinda like receiving a call, to save battery power. but again that is just a guess.
if it were on the whole time is that a problem? if so you have the option to turn it off manually.
when at home, or the office and i'm connected to wifi, i noticed that after i swipe to "wake" the phone back up, the wifi meter is gone and 3G is what appears, after a few seconds, the wifi icon comes back, and 3G dissapears. if i'm not actively using wifi, does the phone somehow shut this feature off until i "wake" the phone back on?
It does not really sleep. I will keep mine on my night stand this time of year to be able to check on the weather. We get some fairly wicked storms in my area starting in the Spring. I put my iPhone in "Airplane Mode" but I leave Wifi on. I know it still works because I will hear it buzz sometimes when I get an email.
on the same issue kinda as before, knowing that the wifi "drops" when the phone "sleeps" for lack of better terms, will it affect battery life by leaving wifi turned on? does leaving wifi on have a very dramatic effect on the battery life? or is it minimal?
It won't affect battery life as the connection isn't open. While the connection is open and you are actively browsing, then the battery will drain faster.
I want to say it stays connected at all times. Why do you I say this? Because turn off your radio and leave WiFi on over night. When you wake up you should have emails. (unless nobody loves you and doesn't send you one)
That right there says it stays connected when the phone sleeps.
That's if the application turns it back on (push would do this or if you have your email set to connect every so often). My example is Gazette (Google Reader RSS application). It does not prevent the iPhone from going into sleep mode and after about 2 minutes (I have mine set to sleep after 1 minute) the syncing stalls until I wake the device, at which time it continues to sync. Other RSS programs like Byline prevent the iPhone from going into sleep therefore keeping the connection open.
Also, I noticed that when waking the device I can see the 3G icon in the top left and then after about 2 seconds the WiFi icon shows up as it connects.
If the phone is asleep or if you have push enabled it will be on, but not constantly. I noticed with wifi when swipe on my phone it will be on 3g then the wifi indicator will pop on