Robin Good: Charteo is the first slide-by-slide online PowerPoint store offering high-quality, professional-looking slides that can be fully edited and customized.
Charteo offers more than 10,000 editable business slides, diagrams, charts and maps for Microsoft PowerPoint. Slides can be searched or browsed via a set of well organized categories.
In general, individual slides in Charteo cost apx. 3-4€, but for most you are also offered a large bundle of similar slides for a largely discounted price (e.g. 62 unique 3D slides designs for 49€).
Once you have picked and selected your preferred slides, Charteo packs them all in a .pptx file that sends to you as a link.
I have tested the service and I am impressed by the good quality and assortment of the designs available.
More info: http://www.charteo.com/
(via Baiba Svenca)