Which dsiware titles have ascii-only string output, because i have a lot of dsiware on my DSi?

Quote
darklink
Which dsiware titles have ascii-only string output, because i have a lot of dsiware on my DSi?

Input not output. And any title which allows you to enter text (e.g. profile name, character name, high score name etc.) which is then saved, and is entered using standard letters and characters (i.e. no special ones specific to that game).

Chart of all ASCII characters: [en.wikipedia.org]

So basically any DSiWare title where you can enter text using those characters and only those characters, and it is then saved, and loaded again in the future.

Is there anything that can be done with the common key?

No.

Just a nice wee update: [bootmii.org] - DSi Exploit.

Source and info: [hackmii.com]

Considering that Nintendo removed the required software for Sudokuhax to function, is there a way that something similar to JailbreakMe could be implemented?

No.