From Flores v. Texas (Oct. 23, 2008) (unpublished memorandum):

Appellant's first three points of error relate to the trial court's exclusion of evidence requested by appellant. That is, appellant complains about the exclusion of evidence concerning (1) the "John Reid" technique that allegedly results in false confessions, (2) the "circumstances" surrounding appellant's written confession, and (3) his wife's conversations with police, which were said to be contained on a compact disc. We hold that appellant has failed to preserve these complaints for appellate review.

In order to preserve a complaint concerning the exclusion of evidence, a defendant generally must make an offer of proof or file a bill of exception to make the substance of the evidence known. See Tex. R. Evid. 103(a)(2); LaHood v. State, 171 S.W.3d 613, 621 (Tex. App.-Houston [14th Dist.] 2005, pet. ref'd). Otherwise, as here, we cannot assess whether the exclusion was erroneous or harmful. LaHood, 171 S.W.3d at 621. However, appellant failed to make an offer of proof, or file a post-trial bill of exception, to preserve his complaint to the trial court's exclusion of evidence.[3]

[Footnote 3:] Appellant suggests that we may take judicial notice of information posted on a "reliable website." We decline appellant's invitation to take judicial notice of the Wikipedia entry for the "John Reid technique." See James Glerick, Wikipedians Leave Cyberspace, Meet in Egypt, Wall St. J., Aug. 8, 2008, at W1 ("Anyone can edit [a Wikipedia] article, anonymously, hit and run. From the very beginning that has been Wikipedia's greatest strength and its greatest weakness.") (emphasis added).

An interesting and reasonable result, which supports the view that Wikipedia shouldn't be relied on for contested questions. For certain uncontroversial matters (such as that the capital of Armenia is sometimes spelled Erevan), citing Wikipedia is probably fine, given that the time of judges, staff attorneys, and law clerks is valuable and best not spent on tracking down The Perfect Source. But when the matter is subject to reasonable dispute, there should either be a hearing -- as with other facts about the details of a case -- or a more elaborate discussion (as with so-called legislative facts that a court uses to determine the meaning of statutory language, develop various common-law rules, and the like).

Thanks to BNA's Internet Law News for the pointer.