I have a set of community sites, related to cruise travel, and I'm looking to allow users to create their own blogs within the site.

I use Joomla, but would rather have a stand-alone program, such as Coppermine, to offer this.

Any programs, or services, which would fit the bill?

You might check with your server and/or godaddy. For a stand alone blogging service within your site I think you will require sub domains.

Well I have sub domains for each separate site. What I'm looking at, is something to install, that lets each portal offer individual blogs to users.

Coppermine is a photo gallery system BTW.

Does your hosting offer installable "add-ons", if so, set it up so Wordpress or something like that available for the users to install when they set up the sub-domain.

I'm aware Coppermine is for pictures and such.

Users are not setting up subdomains. The Joomla installs are each in their own subdomain, not sure where subdomains factor into it.

I simply need something, a blogging package or whatever, that members on the site can use, in the same way they use Coppermine to create photo galleries, but in this case to create a blog.

Users are not setting up subdomains. The Joomla installs are each in their own subdomain, not sure where subdomains factor into it.

???
Should there be a "subfolders" in there somewhere?

Well, what I'm saying is that I am not speaking to the technical setup, aside from saying I use Joomla. I don't care if the tool uses Joomla or not.

I'm trying to find software that will do the job.

Then use Wordpress

Maybe it can do the job, but in my use and observation of Wordpress, it is best used for single user blogs, or collaborative projects.

The idea here is to have something people enter and name and title, and it gets listed within a menu structure, such as picture galleries do in Coppermine and such. Likewise, people can't go in an alter other people's blogs.