Examples of things you can add to a wiki page:

Basic Formatting

Bold (b) Italics (i) Underline
  1. Numbering
  • Bullets
Horizontal Line

Hyperlink

The picture button


lets you insert:

Photographs

abby1.jpg
A sample photo

Documents

Microsoft Word


Adobe Acrobat


Anything!!!


Audio



Widget Button


Embed any video -- copy the embed code. It is compatible with - youtube, teacher tube, google video, yahoo video, blip .tv (and many more.

Audio

Odeo, imem and others (above I uploaded the Mp3)

Calendar

Google Calendar, Airset, 30, others


Spreadsheets

NumSum EditGrid, Google Docs and Spreadsheets, others

Document

Scribd, Bitty, others

Polls

Survey Gizmo

Rss Feeds

(from anywhere -- Delicious is very useful.)

Chat and IM

Gabbly, Skype, YackPack, Meebo

SlideShow

Slide, Flickr, other (slideshare.net works too.)

Map

Google Maps, other

Bookmark

Delicious

Other HTML


My New Favorites


ToonDoo


Slideshare.net (now you can slidecast)

Ustream


Classtools.net (Venn diagrams, Hamburger diagrams, timelines -- see my class wiki for how I used this for a timeline project.)
Twitter