To make it easier to find sub-forums from the main forum page, I think it would be very useful to have links to sub-forums under the parent forum on the forum homepage.

For example, under 'Gear' on the forums page, you could have 'Sub-Forums: Cases - Headphone - Car Solutions'

This would make it easier to find sub-forums and reduce the server load a little bit if people went straight to a sub-forum rather then the parent forum and then the sub-forum that they wanted to browse.

Just an idea, I think it would be really useful and it is very easy to add.