iH8Sn0w has released iFaith 1.3, an update to his tool that dumps the SHSH Blobs of your current firmware, even if Apple is no longer signing that version.

iFaith v1.3 - Release Notes (read it all!)
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For iOS 3.1.x/3.2.x/4.0.x/4.1/4.2.1/4.2.6/4.2.7/4.2.8/4.3/4.3.1/4.3.2/4.3.3
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~Important~

* DFU Loops were being caused on devices that had the factory certificate.
On this new version. When building the signed IPSW. If you were getting
a DFU loop, say "NO" to the prompt about using the standard
signing certificate.
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* You can now use TinyUmbrella blobs to build a signed IPSW.
[Change Filetype in browse dialog to "TinyUmbrella SHSH blobs".]
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* Now adds ECID to beginning of the SHSH filename after dumping.
* Now adds ECID to beginning of the IPSW filename after being built.
* Cleaned up code + payload.
* Its not possible to add iPad 2 support until a bootrom exploit arises.
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Many Thanks to @sbingner & @Sk0ODaT
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Download at: iH8sn0w.com
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It supports the following devices:

iPhone 3G[S]
iPhone 4
iPod Touch 3G
iPod Touch 4
iPad 1G
Apple TV 2