Arduino - Coding without delays using program Ticks

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attachInterrupt(function, period)
Calls a function at the specified interval in microseconds. Be careful about trying to execute too complicated of an interrupt at too high of a frequency, or the CPU may never enter the main loop and your program will 'lock up'. Note that you can optionally set the period with this function if you include a value in microseconds as the last parameter when you call it.

Completely removes the need for anything in the loop.

Give it a go:

#include <TimerOne.h>

void setup() {
  DDRB |= _BV (5); //pinMode(13, OUTPUT);
  Timer1.initialize();
  Timer1.attachInterrupt(blink, 500000);
}

void loop() {
}

void blink() {
  PINB |= _BV (5);  // digitalWrite(13, !digitalRead(13));
}

Also has the advantage of operating completely independently of "the loop", leaving it free for other things.

Not saying it's a better way, but another different way that might serve a different purpose.

Incidentally, I used this opportunity to "big up" that nice Mr Nick Gammon's post listing the direct port numbers. I have it pinned on my wall for permanent reference!

Simply replacing:

pinMode(13, OUTPUT);

with

DDRB |= _BV (5);

and

digitalWrite(13, !digitalRead(13));

with

PINB |= _BV (5);

takes it from 1,478 to 904 bytes saving 574 bytes. Reasonably significant. (Your example is 980 bytes, so actually smaller code without "fiddling"!).