Jitterbit connecting ERP and SFDC

We are using Jitterbit to move data from an old legacy ERP system into Salesforce.com. We are currently using it in our sales and marketing department but we are considering using it as well in our HR department to further integrate data between their systems. Because I pull information from an old ERP system, I do have to manually clean the files before import using Jitterbit. It does take a good deal of time and focus to ensure my imports are going as needed. I would like to see an automatic lookup field in Jitterbit for the Salesforce.com record ID. That would make my imports go much more quickly. I really like the field mapping tool. It's very easy to use and to add various rules and filters. It's a good solution for our needs. It's helpful to have some technical savvy before diving in.