CNetX Pocket Slideshow 1.51
the author of this app says:
Pocket SlideShow lets you browse quickly and easily through your PowerPoint presentations on any Windows Mobile / Pocket PC device. You can browse slide previews, thumbnails, read comments associated to your slides and even rearrange slides or display them full screen with transition effects.
It includes a full-screen presentation mode, thumbnail viewing that allows you to change the order of slides, a file explorer for opening files from your storage and ClearType rendering for improved readability. You can adjust the font size according to your preferences, and take advantage of zoomable and scrollable slide previews.