If I purchase the book, do you consider it fair use for me to scan it in, OCR it, convert the resultant text into whatever format I want, and use it that way (for personal use, that is)?

We had an interesting chatterbox conversation this morning (EDT) in which I defended that position, which seems like an intuitively reasonable one. However, as footpad and Beatnik pointed out (with helpful references from footpad), it is not based in actual law (hate that).

Specifically in U.S.C. title 17, section 106,

Subject to sections 107 through 120, the owner of copyright under this title has the exclusive rights to do and to authorize any of the following:

1. to reproduce the copyrighted work in copies or phonorecords;

Ah, but you will say "fair use!" And indeed, that's where we came in. That's covered in section 107:

Notwithstanding the provisions of sections 106 and 106A, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright.In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include -

1. the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
2. the nature of the copyrighted work;
3. the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
4. the effect of the use upon the potential market for or value of the copyrighted work.

The prevailing view would seem to be (though I quote pretty much everybody in saying "Fair use is not an exact doctrine") that copying a chapter for personal use is acceptable, though arguably only if there's a "valid" reason (e.g. to teach about, criticize, or comment on it), but copying an entire book is not permissible under any circumstances.

In the particular case of the ORA Perl books, since they do sell an electronic copy, you are doing them (in some sense) economic damage if you produce an electronic copy without their permission, even for personal use--and the guiding principle of copyright case law (at least according to this guy) is to protect copyright holders from economic damage. Hence, the hypothetical I proposed (and I think what you're proposing here) would be illegal, unless prior permission was secured from O'Reilly.

As a practical matter, nobody's likely to bother suing you for the US$80 the Perl CD Bookshelf lists for, since it's less than the small claims filing fee in many places, but as a legal matter, they could.

Most of this I cribbed from Findlaw (courtesy of footpad) and Stanford's fair use site, should anyone care to poke around for the details.