Suggested improvement to contact import mechanism

When importing records into CiviCRM, the import will often fail to complete successfully (for example because of a duplicated external identifier). The problem is that there is often no real way of easily finding out what record(s) is/are causing an import to fail (usually 1 or 2 in 500 or so), without iteratively breaking the upload into smaller chunks. Is there a way to implement an error message (along similar lines to the type raised in R) which specifies which row/contact is causing the error? Improved error reporting in this way could save a lot of hassle when trying to troubleshoot problems.