Another tidbit from JKR's site (semi-spoiler)

[Steve]

--- In HPFGU-OTChatter at yahoogroups.com, "justcarol67"
<justcarol67 at ...> wrote:

> > > Has anyone noticed that if you click on "Ancient Runes Made
> > > Easy" on the Links page, ...
> > >
> > > Carol
> > >
> > 
> > Now Tonya:
> > 
> > Carol,
> > 
> > Mugglenet has that one listed today along with two others.  
> > Go check it out!!
> > 
> > Tonya
> 
> Thanks, Tonya. BTW, does anyone think that the lightning bolt 
> might be a Sowilu rune? Compare the picture revealed by Peeves
> on the Links page with this:
> 
> http://www.bewitchingways.com/runes/runes.htm
> 
> I always thought the scar was an Eihwaz rune because of the 
> symbolism and Hermione's reference to missing that question 
> on her OWL, but this one's a better match in terms of shape. 
> And "Ancient Runes Made Easy" suggests that runes will be 
> important in Book 7. ...
> 
> Carol
>


bboyminn:

Carol, I've always thought it was Eihwaz too.

Look at the definitions from another Runes site.

http://www.stevenforrest.com/runes.html

EIHWAZ:  Defense, Striving
Although you are facing a trial, you are protected. The skill you most
need lies in trusting that protection.  Unforeseeable power and wisdom
await you if you avoid panic or precipitous overreactions. Be strong,
and judiciously bold, and no harm should come to you. This is the Rune
of TESTING.

SOWILU:  Sunlight; Life Force
Primal vitality is the issue now. The spark of life within you must be
fanned and renewed. What feeds your spirit and your Self? What gives
you joy and energy? Turn to those sources now, and restore your
elemental enthusiasm for living. This is the Rune of WHOLENESS.

While I can see ways to apply Sowilu to Harry, and admit that Sowilu
looks more like a lightenig bolt, Eihawaz is practically a summary of
the HP series. 

Further, I do think it is significant, but I'm not sure how. Though I
vaguely remember reading JKR saying that the shape of Harry's scar was
not significant. Of course, just becaure it isn't 'significant'
doesn't mean it can't be symbolic.

For what it's worth.

Steve/bboymin