Definitely not the souvenir you want to bring back to the family. If you've never seen the effects of bed bugs (and the difficulty of getting rid of them) consider yourself lucky. Back in college one of the sorority girls got them (how no one knows) and in a few days the entire house was infested. Getting rid of them took weeks.
Avoiding them is probably beyond your control, but with some simple diligence you can spot them and stop the problem before they end up in your luggage and back in your home. One habit I've picked up lately is taking all my clothing directly from my suit case to the washing machine (and all the dry cleaning in a sealed bag) just in case.
http://hotels.about.com/od/hotelsecrets/a/bed_bugs.htm
http://www.msnbc.msn.com/id/11877871/