The dog days of summer have a way of persuading us that a pool is a must-have item. For most, the beating sun of summer assures that a pool -- and the upkeep it requires -- is an investment that will be well-enjoyed. Overspending on a pool bigger or more opulent than your belly-flopping, Marco Polo-playing kids can appreciate can be a sure path to drowning in debt. A personal grotto may look spectacular, but is it any more refreshing than a far cheaper above-ground-pool? Worst of all, over time, as others around you up the ante with high-end pools and accompanying landscaping, you'll probably spend less time soaking in the view of your once-prized possessions as thinking about what others have. At least your family will still get years of enjoyment out of your pool. The athletically inclined (or, perhaps put better, athletically hopeful) may spend at least $10,000 and up to $35,000 or more on a lap pool. A decent "swim current generator" is cheaper, but can still cost in the ballpark of $5,000. They are great investments for those with not only the money, but the space to accommodate them and the real desire to use them. But be warned, if you are more likely to end up merely dangling your toes in the water while sipping a frozen daiquiri, it is unlikely you'll muster the ambition needed to make it a worthy investment.