You can query the [WebLink][1] SObject to find the information you need:

    Select w.Width, w.Url, w.SystemModstamp, w.ShowsStatus, w.ShowsLocation, w.ScontrolId, 
    w.RequireRowSelection, w.Position, w.PageOrSobjectType, w.OpenType, w.NamespacePrefix, w.Name,
    w.MasterLabel, w.LinkType, w.LastModifiedDate, w.LastModifiedById, w.IsResizable, 
    w.IsProtected, w.Id, w.Height, w.HasToolbar, w.HasScrollbars, w.HasMenubar, w.EncodingKey, 
    w.DisplayType, w.Description, w.CreatedDate, w.CreatedById 
    From WebLink w

  [1]: http://www.salesforce.com/us/developer/docs/api_meta/Content/meta_weblink.htm