Some people claim that ear size and shape is related to intelligence. For example, this writer.
Has any real research been done on this?
This isn't going to be a very satisfying answer because I don't think there have been any reuptable studies on the subject.
Claims like this fall under the outdated (and largely debunked*) "disciplines" of physiognomy and anthropometry (also related to the more well-known pseudo-science of phrenology). It seems that there hasn't been much recent study on this subject.
* A free pre-print draft of this paper is available from the author's website.
Auribus est longis aliquantum, stultus et amplis, est vafer est multæ garrulitatis homo.
I am not sure if the author wrote this herself or if it is a quote, however, the translation the author provides is a bit off, so I am guessing that she is actually quoting an old adage. I haven't been able to find any other mentions of this quote, though. Here is my (hopefully more accurate) translation from the Latin:
Men with moderately long ears are eminently foolish, sly, and very talkative.
The Chinese, on the other hand, believe that long ears predict longevity and thick ears predict great wealth. However, that may actually be a source of the claim, since it is generally accepted that wisdom increases with age (thereby, old people with larger ears are more wise).
In fact, the only relevant recent study I could find is one that positively correlates ear length with age in Japanese men. Oddthinking also found a similar study in the comments above. Therefore, people's ears do continuously become longer/larger as one ages. If we equate age with "wisdom", then ear length/size should be a good predictor of that. Older people are also more likely to be wealthy than young people (since they have had more time to amass a fortune). I couldn't find any studies supporting the claim that wealthy people are perceived to be more intelligent by virtue of their financial success, however, I think that is a reasonable thing to assume. Under that assumption, large ears should also be positively correlated to perceived intelligence (although not necessarily actual intelligence, since there is actually no correlation between IQ and wealth). There is, however, an actual correlation between IQ and income (cf. the previous link).
As for studies that actually compare an intelligence metric like IQ to ear size, I haven't been able to find any.