An A319 crew approaching an airport VFR captured the glideslope before the localizer and began a descent before identifying the airport. The false glideslope descended them early until the EGPWS alerted and ATC called low altitude alert.

Narrative

We were on approach to ZZZ and approximately 12 miles from the airport at 3;000 FT MSL. Cleared direct to FAF and asked to report the field in sight. We began to configure with flaps 1 degree and then flaps 2 degrees. The Captain stated that he had the field in sight; and I thought that I did also; and we were cleared for the visual to Runway 36. It was going to be a 90 degree turn from our heading to final and the Captain called for flaps 2 degrees. The glideslope was active captured but the LOC was not active yet. I saw the Captain put 1;900 FT in the FCU and begin a turn toward the airport. I looked outside quickly for the airport and the Captain called for flaps 3 degrees and then flaps full landing check. I verified that we were still on the GS (it was centered right on) and selected flaps 3 degrees and full. I grabbed the checklist and was looking heads down to find the correct checklist and began reading and verifying the landing checklist. As I was reading the flaps full; full and green we got a call from ATC querying as to our altitude stating that the minimum altitude in our area was 2;400 FT. At that time we got a 'Terrain; Pull up' warning from the GPWS. The Captain executed the recovery and we climbed back up to 2;400 FT. We followed ATC's instructions to the airport and landed.