Consider for a moment one of Pittsburgh’s oddest development trends: Over the past 10 years or so, plucky entrepreneurs have been transforming old and abandoned churches into bars, cafés, and nightclubs. Is it a testament to the industrious nature of the Steel City, or just plain ol’ blasphemy? You be the judge.

A restaurant and brewpub that serves some of the tastiest gourmet pizzas in town, The Church Brew Works (3525 Liberty Ave., Lawrenceville, 412/688-8200, www.churchbrew.com) opened just over a decade ago in the shuttered St. John the Baptist chapel. Sure to be especially offensive to the ultra-devout are the brewpub’s steel and copper tanks, which occupy the place of honor upon the altar. Mother Mary pray for us.

Located in the industrial burgh of Millvale, St. Ann’s became the site of Pittsburgh’s most radical church transformation when a recording studio by the name of Mr. Smalls (400 Lincoln Ave., Millvale, 412/821-4447, www.mrsmalls.com) moved in. Small’s has since grown to become one of the city’s most popular concert halls, and now serves up an almost nightly mix of punk, reggae, and hip-hop.

Once a Presbyterian church servicing Ukranian immigrants, Charlie Murdoch’s Piano Bar (1005 E. Carson St., South Side, 412/431-4256, www.murdochsrocks.com) is now one of the only two dueling piano bars in the city. Even better than the elegant double staircase and the massive rectangle bar are the stained-glass windows, which features classic Catholic imagery. Makes you feel a bit guilty by your fourth or fifth Yuengling, but what the hell?

Should you find yourself in the depths of South Oakland with a hankering for a bit of the ol’ hubble bubble, stop by Sphinx Cafe (401 Atwood St., 412/621-1153, www.sphinx-cafe.com), an Egyptian-themed hookah bar where wide-eyed college freshmen inhale hits of apple tobacco in between sips of herbal tea and mango smoothies. Sphinx is housed within a disused church of indiscernible denomination. A faux-Rastafarian employee, however, has informed us that the structure was clearly of the Presbyterian persuasion, on account of the stained-glass windows and stuff.

One of Pittsburgh’s most recent sinful transformations took place in (where else?) the Strip District, where Altar Bar (1602 Penn Ave., 412/263-2877, www.altarbarpittsburgh.com) can now be found. A purportedly naughty nightclub offering ”three levels of tantalizing pleasures” along with a sound and light show, deejays, and drink specials, we’re not entirely convinced that the Father, the Son, or the Holy Ghost would green light this particular project. Then again, it doesn’t look like anyone’s asking.

Assuming you’re game for a trip to the suburbs, and assuming you’re the type who considers a zoot suit and a Big Bad Voodoo Daddy CD appropriate accessories for the weekend, you may indeed find your own private Idaho at Cefalo’s Restaurant & Nightclub (428 Washington Ave., Carnegie, 412/276-6600, www.clubcefalo.com). A lounge and restaurant where the spirit of the Rat Pack is celebrated within the bricks and mortar of the structure formerly known as the First Presbyterian Church of Carnegie, Cefalo’s boasts frequent live music and a cozy and professional dining atmosphere.

Finally, there’s The Union Project (801 N. Negley Ave., Highland Park, 412/363-4550, www.unionproject.org), a multipurpose space located inside the former Union Baptist Church. Quite unlike the aforementioned locales, The Union Project is the sort of place where good deeds are done on a regular basis; visual artists work here, community organizers organize here, and inner-city youth gain valuable skills and knowledge here, such as the importance of cultural diversity. The Union Project also has its very own café, the Union Station, so feel free to stop by if you’re interested in simply poking around. To make a financial donation to The Union Project, call or visit the organization’s website.

And, by the way, if you’re planning on patronizing some of the aforementioned businesses but still haven’t settled on accommodations, consider bunking down for a night at The Priory (614 Pressley St., 412/231-3338 or 866/377-4679, www.thepriory.com), a charming B&B on the North Side that was once a Benedictine monastery. It’s within easy walking distance of Downtown, breakfast is served inside the old refectory, and wireless Internet access is available in all rooms and throughout the premises.