I recently described how I have twice found photos of family on eBay in the past three years or so (See If You Aren't Searching For Family On eBay You Should Be). Individual photos are not the only items you should be looking for. Among other things that might mention your ancestor are:
Yearbooks (high school and college): If a photo alone isn't enough to get you to purchase a yearbook, you may find other tidbits that can help shape your understanding of your ancestor. Were they a member of the chess club or volleyball team? Perhaps there is a quote by your ancestor or they were listed as “most likely to. . .” If you're not sure if your relative was in a particular yearbook you can always contact the seller and ask. They may be willing to check if it means they'll make a sale. Before you purchase a Kalamazoo area yearbook be sure to check the Kalamazoo Public Library (KPL) website for online yearbook images. This page lists the yearbooks that the KPL possesses. If there is an asterisk by a particular yearbook it means that photos from that book are indexed in the Local Information Database. You should also visit Kalamazoo County Genealogical Records and look for your surnames in the "Schools" category to see if there is a photo or other mention there. Keep in mind that not all photos or names throughout these yearbooks are indexed and that for the early ones (at least 1939 and earlier) only photos of seniors are included. If anyone in your family attended Western Michigan University you'll be happy to know that you can find digitized yearbooks through 1975 here, thanks to the WMU Archives.
Business items (ads, letterhead, photos, postcards if it was on a main drag in town): If your family owned one business you may find some ephemera that has survived. Wouldn't it be fun to have an ad from the family store framed and on the wall?
Community/church cookbooks: These often have the name of the recipe submitter. You might be able to find an old family recipe that you could bring to your next family gathering. To hear more about using family recipes to learn about your female ancestors and possibly get hints to their ethnicity I encourage you to listen to the Genealogy Gems podcast episode 137 in which Lisa interviews Gena Philibert Ortega about this topic.
Old maps: You might also consider purchasing an old map of your ancestral town so you can mark where your ancestors and other relatives lived (see Mapping thePast). You can then see at a glance how far they lived from other relatives or from their places of work.
Diaries/Letters: While it is rarer that you'll find these sorts of items, if you do it could be a gold mine of information. I recently searched the book category at eBay and came across a diary and a labeled baby book with photos, both from the 1930s.
If you haven't searched for family on eBay don't be intimidated. Start with something small like searching through the photos in a particular area. Once you've looked through the backlog, keeping up is easier if you sort the results by “newly listed” and select the category you're interested in (photos, books, etc). This way you won't have to wade through items you've already viewed.
However, if you're attempting to find artifacts in a large city this strategy may not be feasible. If you're looking for the needle in the proverbial haystack eBay alerts may be a better option. Choose Advanced to the right of the search button at the top of the screen. Type in your search terms, select a category (such as collectibles) if you wish and click the box to “Save this search to My eBay.” You will receive an email when your search yields results. You can always view your saved searches in My eBay and see when new items are found that match a particular search.
You never know what you might find. Happy hunting!