Are there limits to number of INSERTS inside a Transaction?

I can tell this is going to be a good day, it's my second stupid question
of the day.  Thanks to Alex Bolenok for a complete, concise answer to my
first question!

Now the question:  Can I do too much inside a transaction?  In other
words, say I was importing a file with 100,000 records and I wanted
to make sure either the whole thing imported or none of it; would it
be a bad idea to do ALL of the inserts within a single transaction?

Are there any limits to the number of inserts/updates within a transaction?

Ken Causey