Flickr
Sorry if you know all about this but I have just discovered how good Flickr is.
Over two years ago when I renewed my phone contract, I got loads of free storage space on Dropbox. That was brilliant and I uploaded several hundred photos thus making them safe and freeing up space on my hard drive.
Just before my two years was up I started to get nagging emails saying that doomsday was coming and I would have to start paying for my Dropbox space and it wasn't cheap.
Consequently I removed most of the material from Dropbox and burnt it onto CDs. No problem, but which CD holds what?
I have just discovered that Flickr gives you 1 Terrabyte of storage space FOR FREE 
That is a lot of photos.
The added bonus is that all the family and friends can share my uploaded shots. In addition I can easily Tweet them or publish them on Facebook.
So, if you have a lot of shots of your trips, put them on Flickr. Proper job!