New applet, fuser, from Tony J. White.  (Needs some cleanup.)
diff --git a/procps/Config.in b/procps/Config.in
index b4832db..8a22a5d 100644
--- a/procps/Config.in
+++ b/procps/Config.in
@@ -13,6 +13,14 @@
 	  memory in the system, as well as the buffers used by the kernel.
 	  The shared memory column should be ignored; it is obsolete.
 
+config CONFIG_FUSER
+	bool "fuser"
+	default n
+	help
+	  fuser lists all PIDs (Process IDs) that currently have a given 
+	  file open.  fuser can also list all PIDs that have a given network
+	  (TCP or UDP) port open.
+
 config CONFIG_KILL
 	bool "kill"
 	default n
@@ -103,5 +111,6 @@
 	  the system has been running, how many users are currently logged
 	  on, and the system load averages for the past 1, 5, and 15 minutes.
 
+
 endmenu