I uploaded my entire catalog to LibraryThing beginning yesterday. That website provides a way to allow students, faculty, and administrators to see which books your library holds. Thus far I have been impressed with how relatively easy the process was.
All I had to do was export a file from Alexandria and then upload it to LibraryThing. The first time I attempted the upload, it didn't work because the file was too large. However, after I went back and only exported the ISBNs, it worked fine. The original export just had too much data.
I have now had several teachers try it out. The search engine is adequate, so it can really help students at home wanting to know if we have books on a particular topic.
You can see our catalog here.