It's no one's fault, but the word me gets a bad rap.
An idea a lot of us carry over from our childhoods is that me is always incorrect. Who doesn't remember this scenario:
YOU: Is it all right if me and Tom go to the park and play?
Despite our parents' good intentions, the correction was often left unexplained. Therefore, it's easy to think that me is always wrongand to conclude that this is based solely on politeness, i.e. allowing another's name to go first. Unfortunately, this misconception leads to constructions like this:
PARENT: Tom and I.
YOU: Is it all right if Tom and I go out and play?
These apples are for Ned and I.
It turns out that in this second instance, it's correct to say, "These apples are for Ned and me." You could even put the "me" first and it would still be correct (shock! horror!).
Now, I could natter endlessly about subjects and objects and bore everyone to tears. Instead, here's a quick test you can do to check the correctness of I versus me, and it flies in the face of the "politeness" logic: take your friend out of the sentence completely and see how it sounds. Here's how the test works:
Situation 1. "Is it all right if Tom and [I / me] go to the park?" Remove "Tom and" from this sentence and you have the following:
"Is it all right if I go to the park?" (Sounds good.)
"Is it all right if me go to the park?" (Sounds like Cookie Monster.)
Situation 2. "These apples are for Ned and [I / me]." Remove "Ned and" from this sentence and you have the following:
"These apples are for I." (Sounds creepy.)
"These apples are for me." (Sounds good.)
That's the test. It's a great little tool. Just be sure to leave an apple for Ned.
Sources: Gregg Reference Manual and Bloomsbury Grammar Guide