Box.net‘s File Sharing app allows social network users to upload and share files of all kinds on their profile pages. It’s simple to set up a box.net account right from within the application, and once that’s done it’s easy to upload file and manage the folder structure you want.

I tested this within Ning, where it’s available within the current set of OpenSocial offerings. Depending on the kind of file you upload, you may also have the option to edit the file via the web; this service is provided through box.net by zoho.com. Unfortunately there was an error with this functionality while I was testing and I wasn’t able to edit the file. There’s also a preview function for many file types.

Via the app settings you can turn off downloading for mp3 files that you upload, and you can change the view and order of the file listings; the vertical height of the app updates on a page refresh to accommodate the number of files that you’ve added.

In general the box.net opensocial app is very well done, and it should be a terrific resource for network members to make files of all kinds available to their peers. Recommended.

Last.fm‘s My Favorite Music app lets you display music that you like, and it lets you and other visitors to your profile page listen to snippets and some full length tracks in-page.

If you have aLast.fm account, you can also attach it to the application, and it will provide a list of you recently listened to tracks.

Generally speaking the experience is not quite as slick as you get from Last.fm’s Facebook app, but it features the same basic functionality.

Links in the OpenSocial app (this is also true of the Facebook app) take you back to Last.fm; having the ability to play music inline and explore another user’s musical taste is a nice addition to profile pages. I found a few non-specific errors using this app initially, but they have not been seen again in the last couple of days. Given that this is only the first iteration of the app, look forward to future enhancements and bug fixes.