My only time for hobby programming is on public transit using a myTouch 4G Slide, with no network access (underground). I've installed SL4A. The internal editor isn't usable because my keyboard does not have {} or []. I also installed the modified TextEdit apk, but I'm looking for something with line numbers and syntax highlighting for Ruby, HTML, JavaScript and maybe Python, TCL and Java.
Any suggestions (other than buying additional hardware)?
It's new, but seems good (and it is free). Has syntax highlighting (you can even create your own if you have the desire to). Looking, it seems to come preloaded with syntax files for java, javascript, lua, python, php, html, xml, perl and c.
Jota Text Editor
https://market.android.com/details?id=jp.sblo.pandora.jota&feature=search_result
It's great on my Galaxy 10.1 tab, ok on my Droid X2 phone (sucks in landscape mode on the phone as only the line of text you are typing on is visible that way due to the keyboard taking up 80% of the screen). With a hard keyboard, it might be better.
No interest other than a happy user of the product.
Good Luck!