Long list presentation

Long list presentation

I did read all the posts titled long-list... and my question remains open:

I have about 700 items in a list (displayed as checkboxes) from which the user can select multiple items.

These selected check-boxes are automatically serialized in an ajax call to the server from a JQM single page.

Instead of showing this long list, what are my other options from a design perspective or from a tactical angle? This is important for the mobile and of course the desktop version too.