Looking for a downgrade for my iphone 3Gs that is currently running 4.3.5
I want to jailbreak it and I dislike tethered jailbreaks.

I couldn't seem to find one in the forum, but then again, I'm blind as a bat.

The only way to downgrade to any firmware is to have the shsh blobs for that firmare for that device. Do you have the 4.3.3 shsh blobs saved for your device?

I bought the phone brand new with 4.3.5 already on it.
I have no idea what a shsh blobs is.

Forgive me. I really am not sure what I am doing here.

I updated to iOS 5 and then jail broke it.
All is well now

Hi, I have such situation. I've had jailbroken iphone 4 with 4.3.3 software. I had a physical problem with sound recording mike, and had to take it to repairs under warranty. Prior I've saved SHSH blobs on my pc and restored to original settings, which included upgrading to the latest software iOS 5. I had to do this in order to not to loose warranty on my iPhone. After 2 weeks I've got my iphone from repairs, and what do you know, it is totally new iPhone, with different serial and imei, and iOS 5 on it.
My question is this, can I downgrade to 4.3.3 using saved SHSH blobs on my PC, or they are no use anymore, since this is different iPhone? If not, I guess I would have to look for another way of downgrading to 4.3.3 whithout SHSH, since I want to have unteathered jailbreak.

Hi, I have such situation. I've had jailbroken iphone 4 with 4.3.3 software. I had a physical problem with sound recording mike, and had to take it to repairs under warranty. Prior I've saved SHSH blobs on my pc and restored to original settings, which included upgrading to the latest software iOS 5. I had to do this in order to not to loose warranty on my iPhone. After 2 weeks I've got my iphone from repairs, and what do you know, it is totally new iPhone, with different serial and imei, and iOS 5 on it.
My question is this, can I downgrade to 4.3.3 using saved SHSH blobs on my PC, or they are no use anymore, since this is different iPhone? If not, I guess I would have to look for another way of downgrading to 4.3.3 whithout SHSH, since I want to have unteathered jailbreak.

Unfortunately No. The blobs are device specific. In my experience IOS 5 is very stable. I have been using for 2 weeks now on 2 devices with the tethered jailbreak and haven't had to reboot yet.

There is also a semi-tether hack that at least makes the phone usable until you get to a computer to boot tethered.