iPhone3GS 3.1的朋友有救了....

Cydia 3.1 ECID SHSH service is up now.

From saurik's tweet.

Here's what it looks like

Cydia 1.0.3044-65 running on FW 3.0.1

For non-jailbroken devices, you can register with Cydia server by append
the following line to your hosts file

Code:
74.208.105.171 gs.apple.com
hosts file location

Code:
/etc/hosts on mac
C:/Windows/System32/drivers/etc/hosts on Windows

and then do a restore from iTunes. This will register your device with Cydia server.