The layout at Symbian Signed has changed a bit, if you want the same old signing link, just press Open Signed, but here's an explanation from the website itself:

• Open Signed, has updated and replaced Developer Certificate signing, making it easy for developers to sign applications for limited deployment to known devices, either for testing or for personal use. The online-only option is coming soon.
• Express Signed, a new option similar to Self Certification, is available to all developers, either directly (for those who own a Publisher ID), or via publisher partners (for those who do not).
• Certified Signed, has updated and replaced the mainstream signing option based on independent testing by a Symbian accredited Test House.
• TCTrustCenter, www.trustcenter.de/order/publisherid/dev, is the Certificate Authority for Symbian Signed, responsible for issuing and validating Publisher ID digital certificates (but existing ACS Publisher Certificates issued by VeriSign will remain valid for Open Signed and Certified Signed).

And there is also a sign on mobile system:

What's New( V1.01):
1.Auto change language
2.Save paths is available
3.Support signature with password

Just now this has updated again~
Build2:
Fix:add the translation of "password" of other languages (author's carelessness)

1.install it.
2.run it,press ok button,select sis file.
3.select *.key & *.cer.( v1.01 has supported enter of password.)
4.sign it.(the signed file will be named as *.sisX,and sisx is the same folder as sis)
5.done
enjoy signing on your phone without computer Some Problems may be meet with while using:
1.Only support DSA signature ,& RSA signature is unavailable.
2.The formats of cer & key must be the PEM base64.
3.Once occured error when browsing files.
4.The app wouldn't check the cer,thus you should make sure that it's correct.
5.If it says "KErrArgument(-6)",please check whether the password is right or not.

I heard it can extend signature to 20 years!

Download the program here
Password: phonereport.info