If it is a mac, then I think it will be in a folder called minecraft, not .minecraft. Also, it does that sometimes, so what you need to do is create a folder called mods . Then just put the downloaded mod in there! Easy!
My awesome dragons!
Take a look at my achievements!
97% of teenagers would cry if they saw Justin Bieber on top of a tower about to jump. If you're the 3% who is sitting there with popcorn screaming "DO A BACKFLIP", copy and paste this as your signature.
Okay, so- I guess for MAC OS Lion we don't have a mods folder in our Minecraft. We have to manually create a folder there.
So what you do to get to your Minecraft folder, is click on your Desktop Finder (the background there) and at the top menu is 'Go' (in between 'View' and 'Window').
Click on this and press the 'Option' key on your keyboard next to the 'Command' key down. It will bring up the 'Library' menu item in the drop down list.
Select 'Library' and let off and in there is the 'Application Support' where Minecraft is. Open that folder and at the top of the finder window is the Create New Folder option under the Settings cog as seen below:
I installed Forge and my java is up to date and everything, but when I put my mod (in my case, Pixelmon) in the mod folder it's not showing up in my mods on Minecraft even though Forge is.
So I'm stuck. There.