UBB.threads PHP Forum Software Community Forums Resources and Customizing How Do I? Want to Make a Recent Topics Island

Same place Sirdude mentioned.
Control Panel » Post Island

Name
This appears as the header for the post island.

Cache Time
In Minutes. Higher cache times are better for overall forum performance.

Always Build
With this option checked, this island will always be built even if it's not used in your portal. This would allow you to use the island elsewhere on your site.

Island Type (New topics Only,Recent Posts)

Number of Topics/Posts to display (Your example,10)

Source Forums (Pick and choose)

Then just add the island placement in:
Control Panel » Portal Layout

There is no need to use the custom Island when the post islands will do what you want.