Listed partition in cfdisk, but not listed in /dev?
 

I am trying to make the remaining unused 280mb of space on my hard drive swap space.

It is listed as hda7 in cfdisk. There are no flags, it is logical and of filesystem type Linux swap / solaris.

However, hda7 does not exist in /dev. So, I can't even use mkswap.

What's funky?

Is it in your /etc/fstab?

I vi-ed fstab and no, /hda7 was not there.

Should I manually add it there?

As long as it is formatted as swap (I believe you said it was), then yes.

I think the way it would be written is...

/dev/hda7 swap swap defaults 0 0

or something very close to that (this is mine, minus the hda7).

Yes, this should solve it.

The risk level for editting the fstab is pretty low, right?

I just did it and it worked. There's swap spaceon gKrellm.

Thank you so much.

No problem :)
Just to make sure you know, fstab means "filesystem table," and tells your box what filesystems are available, and where to put them when they're called for. This file, in concert with mtab, or mounted table, is how Linux handles mounting and unmounting filesystems.