It's interesting what Fr George said about "Rum-influenced" churches. The impression he gives is that weekly communion without confession is an ancient practice in the Greek church, but my understanding is that weekly communion is a fairly recent practice, and has become the norm in most (New Calendar) Greek churches due to the influence of an article about frequent communion by Fr John Romanides. He apparently argued that not receiving at each liturgy, unless one had a canonical impediment, was actually a kind of heresy (!). If anyone knows of this article, or can tell me I'm wrong about this, please say something.
I know that in the Early Church, weekly communion was the norm, but it is pretty much beyond doubt that for the past millennium or so, until a few decades ago, weekly communion has not been normative for the laity in the Orthodox Church, and that lay people, when they received, always prepared for it with fasting, confession and a special prayer rule.
In most Old Calendar churches weekly communion is still rare, except in the Boston-based HOCNA jurisdiction, which is heavily influenced by Fr Romanides' thought in other respects, so I don't think they're too representative.
The actual practice I observe at my church, St Markella's, is that practically no lay people receive every week, but when they do receive they always confess beforehand. My impression from the Russian jurisdictions (ROCOR under Met Hilarion, and the RTOC under Bp Stefan of Trenton) is the same: confession always comes before communion. Admittedly this sometimes takes on a kind of legalistic aspect, as in 'you can't receive unless you confess', even if your sins are pardonable. In the same way, not fasting for three days before receiving is often seen as a serious impediment, even though the amount of fasting required is really up to the confessor. I think traditionalist Greeks are more prone to this mentality, but not so much traditionalist Russians.
As for confessing without necessarily receiving afterward, it is quite possible, especially if one has committed a mortal sin that might form an impediment to communion, but which still needs to be confessed as soon as possible. It is also possible to confess at regular intervals, say every month or every other week, or even every week, without necessarily communing each time. Since in traditionalist churches fasting is also a requirement for communion, many may not be willing to fast so often, but would still like to partake of some sacramental grace by confessing their sins, whether mortal or pardonable.