DC9 CREW WAS REQUIRED TO CONTACT TWR ON THEIR OWN VOLITION.

Narrative

UPON CONTACTING BHM APCH CTL WE WERE TO DSND TO 2500 FT ON 220 DEG HDG AND RPT THE ARPT IN SIGHT. AFTER A 30 SECOND SEARCH WE HAD THE ARPT IN SIGHT BUT APCH WAS NOW TALKING TO ANOTHER VFR ACFT AND CONTINUED THIS CONVERSATION FOR ABOUT 30 SECONDS. AT THIS TIME; WE WERE APPROX 1 DOT HIGH ON THE GS; FULLY CONFIGURED; AND AT MINIMUM APCH SPD; AND LEVEL AT 2500 FT. WE ATTEMPTED SEVERAL TIMES TO NOTIFY APCH THAT WE HAD THE ARPT IN SIGHT BUT SUSPECT OUR XMISSIONS WERE BLOCKED BY THE OTHER ACFT'S CONVERSATION WITH BHM CTL. THE CAPT TUNED-UP TWR AND RPTED THE RWY IN SIGHT. THE TWR CLRED US TO LAND ON RWY 23 WHICH WE DID WITHOUT FURTHER INCIDENT. HAD TWR NOT CLRED US TO LAND WHEN HE DID; WE WOULD HAVE HAD TO MAKE A MISSED APCH. AS WE WERE TAXIING IN TWR SAID THAT APCH HAD NOT CLRED US FOR THE APCH AND TO CONTACT THEM BY PHONE. CORRECTIVE ACTIONS: APCH CTL SHOULD TRY TO KEEP LONG-WINDED CONVERSATIONS TO A MINIMUM WHILE OTHER ACFT ARE TRYING TO RPT THE FIELD IN SIGHT. HE COULD HAVE TOTALLY ELIMINATED THIS SIT BY JUST CLRING US FOR THE ILS RWY 23 INSTEAD OF AWAITING OUR VISUAL CONTACT WITH THE FIELD.