Can anyone tell me what these shadows mean?

I'm thinking that those shadows, or "Larval Stalkers", are manifestations of Cheryl's anger/sorrow/despair.

They seem to appear at the school a lot.
Lot's of bad stuff happened to her there;
Which gave me this impression.

My interpretation is similar to Restoration's.

They hang out in areas that represent traumatic experiences for Cheryl. Whenever you find one, its usually crying and curled up--and, until you approach it, it seems completely absorbed in itself and unaware of Harry. When it does finally notice you, it flees as if its ashamed.

I think the places and scenes where you discover the larval stalkers symbolize episodes in her life that caused Cheryl great suffering, and that she constantly dwells and obsesses over.

They kinda remind me of SH the movie in a sense, of Dark Alessa, always in places which were bad for alessa. But yeah, The above is correct, If i see one during the game i know im on the right track

I believe that the teacher that Cheryl had a relationship with was the Chemistry teacher,
because of the Larval Stalker there.

Does anyone think so, too?

Yea, that would make sense. Also, the room where you catch her with the teacher in the photo part, I think correlates to the chemistry lab in the normal world.

Are you referring to the school's Otherworld paparazzi thing?

Yes.

I just saw it as Cheryl running away from her past, and being scared of her father finding out about it.

They remind me of Jung's Shadow Theory. People's "shadows" house repressed feelings of inferiority, guilt, hatred, fear, and the like. Most importantly, shadows can house repressed memories.

Shadows are said to appear in dreams or visions as darker, same-gendered versions of the person, with possibly distorted features.

Given the Psychology-centric aspect of the game, this sort of makes sense.

The Larval Stalkers were so cute in the first one! All they did was run around a little and fall over, so adorable!

Anyway, I think the Larval Stalker in SM represent Cheryl running away from things she didn't want her father to find out about, like DirtyNorris said.

Personally, I think that these Larval Stalkers have a LOT more meaning to them.
It's just difficult to make them out...

While what's been discussed so far about Cheryl's shades are probably true, I also think that each one running away from Harry not only shows how ashamed about her father finding out might be, but also an attempt to keep him from finding his way to her.

Remember, if all works out, Harry will find her and she will have to face the fact her vision of her father isn't true.

I figured that it was for two reasons:

(1) To show you that Cheryl is going along with Harry on the journey.

(2) To represent the fear that Cheryl had of Harry's progress.

But I like the theory that (3) also:

(3) To show areas where Cheryl was particularly traumatized

About the "Tunnel of Love", I wonder what happened there?
There were 3 larvel stalkers there... Can anyone make a guess what happened there?

It seems that it was the last time she saw her parents together at least somewhat happily. Dunno what voice messages you get on various playthroughs, but I got 2 versions, don't quite remember the second one, but on the first one Harry and Dahlia were remembering the old time when they were in love, then Cheryl dropped in and saying that she is sorry that she ruined Harry and Dahlia's "happy time".

God I want to play the game again! Sadly, I don't have it at the moment

Edit: Although I am wondering what happened in the forest? Is she traumatised because of the party that you hear about through the voicemails?

I think Cheryl got drugged at the forest, and got hurt etc. etc.

I didn't go crazy and try to listen to all the voicemails, but I do remember a party in the woods which I believe Cheryl was at. She sounded sick, and wanted to leave. I can't remember for sure.

And those shadow Cheryls?... sub-conscious reminders o the storyteller of the truth They're, what I would suggest, trying to keep Harry from adancing so that in the end, Cheryl won't have to deal with the truth.

I thought that it wasn't three but one that moved from one place to another as you chased it... was it actually three different ones?

^You're right, it was the same shadow running from spot to spot.