picasa, flikr or others?

I am looking for an easy way to share high resolution photos with my family.
It seems like at every family event we all agree to share our photos with each other, but it never happens. The files are too many and too large to make emailing them practical. It would be nice if we can lock the files so that only those we authorise can see them and / or download them.

What do the rest of you use / recommend?

I use Picasa and have one page of family photos that is set up as a private folder that requires a password to open. The files themselves are not locked, but you can control who has access to the private folder by invitation. It works well for the purpose you are looking for. I am pretty sure that WordPress can be set up in a similar manner, but I haven't tried that with my blog. Both are free and fairly simple to use.

I use Flickr, and absolutely love it!

The quality is superb, I am very happy with it! You can upload ALOT of photos before you run out of space on your free account.

Picasa is my choice and it works well for me.