TiddlySpot is a free hosting service for TiddlyWiki documents from Simon and Daniel Baird. It has been in operation almost as long as TiddlyWiki itself.
TiddlyWiki5 isn't yet built in to TiddlySpot but you can use it by following these steps:
# Sign up for a new wiki at http://tiddlyspot.com/, and remember the wiki name and password
# Fill in the TiddlySpot wikiname and password in the control panel
# Click the "Save Changes" button. You should get a confirmation notification at the top right saying ''Saved wiki''. Saving can take several seconds if you're on a slow connection or working with a large wiki.
#* //This step won't work in Firefox thanks to its default security policy. Google Chrome works fine//
# Navigate to your TiddlySpot URL at http://{wikiname}.tiddlyspot.com/
# You should see a copy of TiddlyWiki5. You can edit and create tiddlers, and click "Save Changes" to save changes back up to TiddlySpot (you'll need to re-enter your password the first time you visit the wiki on TiddlySpot)