Not bad.

The latest version of ruby 2.0 is available here: ftp://ftp.ruby-lang.org/pub/ruby/ruby-2.0-stable.tar.gz .. but nice sed work ;) We could probably just assume if they have any version of ruby 2.0 it's good enough.

Line 98: Tick marks \` have been deprecated in favor of `$()` ([see](http://stackoverflow.com/a/4708569/282720)). But that doesn't matter as 95-102 could be:
```bash
if $(ruby -e'p !!RUBY_VERSION[/^2.0/]'); then
```

As I mentioned in my previous comment, you could pipe wget's output directly to tar. So 106-108:
```bash
append_log successfully wget -qO- "ftp://ftp.ruby-lang.org/pub/ruby/ruby-2.0-stable.tar.gz" | tar xzf -
```