Pidgin Portable is a Pidgin version made by PortableApps.com. Pidgin is an easy-to-use multi-protocol instant messaging client with a tabbed interface, customizable sounds, themes and more. Supports a long list of networks including Jabber/XMPP, Gadu-Gadu, IRC, MicroFocus GroupWise Messenger, SILC, and more. It also includes support for many features such as file transfers, away messages, buddy icons, emoticons and typing notifications.
Plugins are also available to add more features including more networks, security, interface tweaks, and more. Themes are available via an additional download.
Pidgin is cross-platform with clients available for Mac OS and Linux; it supports 80+ world languages.
Other portable versions (note that these are oudated and may not function):