There are several ways that you can have your TiddlyWiki data hosted online, making it easier to access and share your information.

TiddlySpot

TiddlySpot lets you put TiddlyWiki documents on the Web, and edit them directly in your browser. It doesn't yet offer full support for simultaneous editing by multiple users.

DropBox

Many people use DropBox to synchronise their TiddlyWiki documents to make them available on multiple computers. The DropBox iPhone/iPad application also permits read only access to TiddlyWiki documents. See A Personal Knowledgebase Solution: Tiddlywiki and Dropbox

TiddlyWeb & TiddlySpace

TiddlySpace is a full hosted service for TiddlyWiki that allows multiple people to edit the same wiki at the same time. It is particularly focussed on sharing tiddlers.

TiddlySpace is built on top of TiddlyWeb, a flexible architecture for putting tiddlers on the web.

TiddlyWiki Server for node.js (TWS)

TWS by Poul Staugaard is a simple node.js based serverside for TiddlyWiki.

GieWiki

GieWiki by Poul Staugaard is a new serverside for TiddlyWiki that focusses on making TiddlyWiki behave like a real wiki, with preview and versioning of tiddlers, any number of pages in any hierachy, an auto-generated sitemap, comments on tiddlers, fine-grained access control, image upload, recent changes etc. You can see a default instance at http://giewiki.appspot.com/.

ccTiddly

ccTiddly is an older serverside written in PHP to use MySQL for storage. It is no longer under active development, but remains a popular choice for basic TiddlyWiki hosting needs.

TiddlyCouch

TiddlyCouch is an experimental integration of TiddlyWiki with CouchDB.