OT: (or is it) re: cell phone data access

[joe at actionline.com]

Recently, we have been discussing various cell phone plans, and I
mentioned that my current pay-as-you-go plan (Airvoice wireless)
charges only $10 every three months (= $3.33/month) and that gives
me more minutes of talk time than I ever need or use.

The only thing missing (until now) has been data, but now they have
added data (web access) for 33-cents per megabyte.

So my question is, how many megabyte would I be likely to consume
for each 5-minute or 10 or 20-minutes of connect time just for
checking email and google searches for addresses, phone numbers,
driving directions, etc. I have no need for streaming videos or
other such data-intensive use?