The Critical Thinking "Building Thinking Skills" series has some analogies, if I remember correctly. I haven't tried those Mindware ones, but I would bet they're pretty good.

After running some quick Google searches I came up with this list of web resources (I can't vouch for all of them):

edHelper.com (pay site, $19.99 US per year)
EnglishForEveryone.org
Freeology.com
movableteacher.com
RHL School (enter "analogies" in the search box)
Scholastic
Steck-Vaughn (I think that first match is a sample page, but if you like it you might follow up and buy more from the series)
Super Teacher Worksheets

Striving to increase my rate of flow, and fight forum gloopiness. sick