Can you jailbreak a Verizon iPhone for use in Europe?

I have an iPhone 4s and will be spending the next year or so on Europe and would love to be able to use it (without paying obscenely high Verizon roaming costs).

If I use jailbreak my phone with a program like absinthe, will I be able to replace the SIM card with one from a French or Italian telecom company and use it there?

You don't need to jailbreak. Just pop in a prepaid sim from any European carrier. I do it all the time when I go to Europe.

Jailbreak won't help. You've to get it unlocked for using on other carriers. Verizon might help you get the phone unlocked if you've spend at least 1-yr on contract. You can also check with this guy who claims to unlock iPhones for using on other network, mail him to arghyle@rocketmail.com