"Download Wiki" means two different things:
These rather discourage the idea of taking a snapshot of the Wiki for offline use.
Nevertheless, a few subsets of the Wiki can be downloaded from mirror sites for offline reading. See WikiMirrors and http:/ppr/wiki/.
If you really want to download Wiki pages:
Have a favorite WikiWiki page (or two)? Want to download it and want the links to work?
If you're running a Windows OS (we have 98se, WinME, XP-home, and XP-pro hanging around here) maybe you can do what I just did. Navigate to your favorite WikiWiki page with MicrosoftInternetExplorer, then click File / Send / Page By Email. This will load the page into a MicrosoftOutlookExpress email window. Now in the email window choose File / Save As / then go to File Type (change from .eml to .htm) choose the location on your machine that you prefer, now Save. This sets the HTML link BASE to c2.com so that all links will work when the page is re-loaded new from your machine into your browser. As far as copyright infringements, well... since the page was already downloaded to your browser's temp folder, what's the difference? Now, at the moment I am on the 98se machine with I.E. 5.5, but it should be similar for the other Windows OSes and newer I.E. versions. I have a page that I use for navigating WikiWiki that I did this way, and it works nice for me (just update it by re-downloading as necessary to keep current).