First, there is the new revised version of Rahlfs’s “pocket” edition of the LXX:
This is the popular edition of the Septuagint — and the only affordable version with the complete Greek text. Note that this is not a critical text (e.g., there is only a brief critical apparatus). Rahlfs based his text primarily on codex Vaticanus (B), but when necessary (and in his own opinion based on established text-critical principles) he adopts readings found in codex Alexandrinus (A) and codex Sinaiticus (S) so as to represent as closely as possible the “Old Greek” version of the text (i.e., the “original” text). This new â€œRahlfs-Hanhartâ€? edition is a minor, yet significant, revision of Rahlfsâ€™ LXX by Robert Hanhart. This revision is a stop gap measure, since a new critical edition of the LXX Psalms is many years off and there were many small errors in the original edition that needed to be corrected. In addition to correcting small errors, Hanhart also made some modifications to the critical apparatus, including redescribing the way appeals to textual traditions were quantified as well as the inclusion of a number of other uncials and recensions where the first edition only mentioned B, S, or A.
Note that Michael Bird has also recently briefly noted this new edition.
Second, Oxford University Press has just published a useful resource for those interested in the Hebrew and Greek traditions of the book of Psalms:
A Comparative Psalter: Hebrew (Masoretic Text) – Revised Standard Version Bible – The New English Translation of the Septuagint – Greek (Septuagint) (John Kohlenberger, ed.; Oxford University Press, 2007). Buy from Amazon.ca | Buy from Amazon.com
This useful volume brings together the Masoretic Text (BHS without apparatus) and RSV of the book of Psalms in parallel columns on one page, with the New English Translation of the Septuagint (by Al Pietersma) and Greek Septuagint (the first edition of Rahlfs’s Septuaginta) on the facing page. This resource makes it very easy to see how the LXX translator rendered his text, though the differences between the English translations may suggest differences where none exist since Pietersma made his English translation with an eye on the NRSV and not the RSV. One of primary benefits of this volume is that it is far less expensive than Pietersma’s out-of-print stand alone translation of the LXX Psalms (A New English Translation of the Septuagint: Psalms [Albert Pietersma, translator; Oxford University Press, 2000; Buy from Amazon.ca | Buy from Amazon.com]).
John Hobbins has an excellent review of this resource on his Ancient Hebrew Poetry blog.
For more resources related to the Septuagint, see my Annotated Guide to the LXX.