The Health Science Information Consortium of Toronto has a Journal Search feature on their website. The search checks the Consortium's union list, and pulls up titles that may or may not be available for interlibrary loan. Click on the library's name in the results, and information on how to borrow from them, including information for non-consortium members, comes up.
Nicely done, and straightforward to use. Note this only searches publication bibliographic information; it does not search for the articles themselves within the journals.