transit passport stamps

We travel in and out of 8 countries and the only stamps I have in my passport is one entering Amsterdam and one leaving Amsterdam 8 weeks later.

Depends on the route. For Paris to Amsterdam, you'll get zero stamps. You're going from a Schengen visa country to another, and passing through a third. No passport control. Krakow to Budapest would get you at least an entry stamp into Slovakia and one into Budapest. You may or may not get exit stamps from Poland and Slovakia.

You need additional passport pages. The US provides them for free. You have to fill out a form and mail in your passport but you've likely not got ten weeks for that. Alternatively, you can go to a US Embassy or Consulate abroad and have this added in.

Greetings
The only time you would be stamped (possibly) is when entering a non-Schengen or non-EU country and, then, when entering back into the EU and/or Schengen Union. I believe that Poland, Belgium and Slovakia are certainly all EU countries and probably all Schengen, but I would check on the Schengen.

You should alway have a few extra pages because some countries (generally not in the EU), will not allow you to enter unless you have a certain amount of space for stamps (no matter whether they use it or not). Getting extra pages should not be a hassle - go to your closest US consulate/embassy and ask. I live outside the UK and got my passport renewed within two weeks for the regular fee plus the charges for the special delivery packet. The trick the consulate staff showed me was to put a sooner that really need date in the 'need by' date line because they will get it back to you by that date for no extra charge.

Kate

Last month I traveled to Berlin, Budapest, Prague, and then Munich. My passport was stamped twice for each country - an entry and then an exit. So, that's 8 stamps.

The Schengen countries are:
Austria, Belgium, Denmark, Finland, France, Germany, Iceland, Italy, Greece, Luxembourg, Netherlands, Norway, Portugal, Spain and Sweden

So if you don't have a EU passport, you would like be stamped going between Belgium and Slovakia - and between any country on this list and any country not on this list.

Kate

thanks everyone, i think you've swayed me into getting extra pages. i've already contacted my embassy in warsaw and i guess i'll be able to show up and leave with the extra pages the same day (Which is great).

We did not get stamped when enter or leaving the Czech Republic.

The UK is not formal, it's just not a part of the Schengen Union. Which means that many people need a different visa to enter the UK than from the rest of the EU. Thus they need to check all non-EU passports carefully to make sure people have visas if they need them.

In general, you are unlikely to be checked driving or on a train from EU country to EU country (excepting going in and out of the Schengen Union), but you are likely to have your passport checked on a flight - but not necessarily stamped. I didn't have my passport stamped going to Switzerland, but this tends to be because most passports are scanned, so they have an electronic record of your arrival and departure.

I have heard that if you get stamped going into a country or into the Schengen Union, that you should make sure that you have a stamp/get scanned when you are leaving so that there's proof you haven't overstayed. This would always happen in an airport, but not always by car.
Kate

I think the extra pages are prudent, though do not be surprised if you encounter wildly varying practices. If flying, expect that you will be stamped more often, driving across a border or train, less likely. Some countries more stringent than others (The UK is VERY formal about border control even from EU countries). My favorite was entering Czech Republic by car in 2000 from Germany, just slowed down at the border and held up our passports without stopping. That trip we didn't even get stamped coming into Amsterdam, only a stamp flying home from Germany.