Can you export your data from Hackers Diet Online?
If you use The Hacker’s Diet Online, you can export your data in several different formats. Any of the CSV (comma-separated values) formats can be imported by FatWatch, I recommend using the “The Hacker’s Diet Online CSV” option. Then use Wi-Fi Import/Export to send the file to your iPhone or iPod touch.
The only catch is that if you use non-ASCII characters in your comments, they will be exported in a format that FatWatch does not understand. This could be remedied by running the file through a utility script; contact me if you have this problem.
At some point I may add support for the HDO native XML format, but before this question nobody has asked about it.