What ever you're comfortable coding in could work. PHP, Java, Ruby... just need to make sure your machine is configured to run the languauges. It isn't that complicated to set up (depending on your comfort configuring a local web server). Then you can just code a local page to submit to your csv.
That would let you set other fields as you go (such as lead source) very easily. Also could add in comments as you go and not be limited to the fields in the app.
Take it a step further and you could optimize the page for use on a tablet, run a local wifi network and be mobile in the booth as you collect leads.