Excel 2007 : Counting Values and Unique Values within a 1 minute Time Interval

I'm hoping you intelligent people here can help me out. I have a two part issues. First, I need an Excel formula to break up Column A into 1 minute intervals. Second, I am looking for two formulas:

1) Count Unique Values (Alphanumeric) within a time interval (usually one minute)
2) Count All Values (Alphanumeric) within a time interval (usually one minute)

In my attached example there are only 21 data sets. I usually deal with 1000+ data sets, so doing it manually is not an option.

If this should be done in a completely different, I'm all ears.

Thanks for taking your time to help me out.

V/r,
Minh

Thanks, I'll give it a try and let you know.