Sounds like my daughter, who just turned 3 a month ago - she's been a real sassy-pants the past few days. Doesn't want Dad to do anything for her - "Mommy do it!" Whining. Bossing me around - "No, sit in THAT chair! Blow bubbles with me! Do puzzle with me!" Pitching a hissy fit when she doesn't get her way. Being very stubborn and persistent and not backing down. It's especially difficult because I can't do everything she wants me to do - even if I could, I wouldn't because I don't want to reward her for her bossy behavior. I had to work 2 back-to-back overnight shifts this weekend and sleep during the day so Dad was in charge and she always wants Mom to do everything.
She is also extremely social, outgoing, athletic and into everything all the time. She seems to only want to do something for 3 to 5 minutes before she changes her mind and wants something else. All I've heard the past week from her is "I need..." As in, I need to play with Play-doh. I need to go play outside. I need a pen and paper to draw. She's wearing me out. She starts pre-school twice a week in a couple of weeks and for me, it can't come fast enough.
I don't know if she is ADHD or not - it's too soon and only time will tell once she is older and has to go to school beyond preschool. I do know that when we've done Mom and Tot type classes, and now she's just started gymnastics, I have to spend a lot of time and energy redirecting her because often she wants to do anything besides what the teacher is having the kids do, and everything else all at once.
I was just reading "Love and Logic" because of all the other moms on here who have recommended it. In the section about tantrums, they say it's perfectly okay for them to have tantrums - the key is having them do them away from you. It's all about having an audience for them sometimes and you simply let them know that if they are going to behave like that, they can do it in their room. Then they can flip out all they want, you just don't have to hear it or be witness to it. Then they might decide they are not getting the attention they want this way and eventually calm down. They also say that tantrums at this age are normal and in a way are a good sign because it means the child's spirit has not been broken (not that it makes it any easier!)
I know it can be tempting to give a spanking, because I've been there, but on the occasions when I have (and I can count them on one hand, no pun intended), it hasn't worked, and to be honest, it was more because of how frustrated I felt that she was not listening to me. So if she is in full melt-down mode, I doubt a spanking is going to fix anything.
Hang in there, I feel for you... :)