DEVONthink has a quite efficient tagging capability. Especially, the autocomplete feature of the tag bar, at the lower part of a DEVONthink window, saves me a lot of time and provides increased consistency in my tags.

Moreover, I maintain a separate page in my wiki for each book or paper that I have read. There I write all my notes and thoughts about each source. MediaWiki’s name for tag is category and the required markup code for it is the following:
[[Category:tagName]]
As I did not want to insert manually the tags for each source twice I wrote an AppleScript, which converts DEVONthink tags to MediaWiki categories. One item should be selected in DEVONthink before executing the script. The result is sent to the clipboard.

The AppleScript code is the following:
--2011-06-18
--http://organognosi.blogspot.com
tell application "DEVONthink Pro"
set thisSelection to the selection
if thisSelection is {} then error "Please select something"
if (length of thisSelection) is greater than 1 then error "Please select only one item"
set the clipboard to ""
set newCategories to ""
repeat with thisItem in thisSelection
set tagsItem to tags of thisItem
repeat with eachTag in tagsItem
set tagForCategory to eachTag
if tagForCategory is in {"Linked with MediaWiki"} then
set newCategories to newCategories
else
set newCategories to "[[category:" & tagForCategory & "]] "
set the clipboard to (the clipboard) & newCategories
end if
end repeat
end repeat
end tell

You can get the code also from my Github account.