The wikipedia article is a very good overview. Probably if you google around you can find already made presentations (I saw many of them). One important (often overlooked) advantages of RUP is risk management, (I did an entry on my blog about it: RUP and risk management). I believe the initial focus on scope and architectural risks driven by the focus of the inception and elaboration phases, is one of the characteristics that differentiate RUP from other iterative-incremental process. You can contact also your local IBM-Rational office, probably they can easily arrange a presentation (If they smell a sell, they will run to you! ) [ August 29, 2007: Message edited by: Gabriel Claramunt ]
Also look at the "Open Unified Process" which is an open source subset of IBM/Rational's RUP products. It's a free part of the Eclipse Process Framework (EPF) tool that builds and publishes process documentation. You can explore OpenUP through EPF.
A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi