Well, that's going to be tough to beat. Nice work Darrel.

Interesting side note: Using your rlf STATUS,F approach reduced my 13 word version to
only 12 words..;o}
Code:
  	list      p=16F628A
	#include <P16F628A.inc>
	errorlevel  -302    ; suppress message 302 from list file
	__CONFIG _CP_OFF & _BODEN_ON & _MCLRE_OFF & _WDT_ON & _PWRTE_ON & _LVP_OFF & _INTOSC_OSC_NOCLKOUT

	clrf  PORTB	   ; clear port
	rlf   STATUS,F     ; Bank1, clear carry for 1st rotate
	bcf   OPTION_REG,2 ; 1:8 prescaler to WDT

Left
	sleep              ; go to sleep for ~1 second
	rlf	TRISB,F    ; rotate 0 from carry into lsb, then left across trisb
	btfsc	TRISB,7    ; jump to Right once trisb,7 = 0
	goto	Left
	
Right
	sleep              ; go to sleep for ~1 second
	rrf	TRISB,F    ; rotate bit right across trisb
	btfsc	TRISB,0    ; jump to left once trisb,0 = 0
	
	goto	Right       ; loop until trisb,0 = 0
	goto	Left        ; now rotate back to the left

        end