Macworld formulates word of HP’s foray into iPhone application development, and it’s both nostalgic for calculator enthusiasts, and interesting from a premium price point:

When run in landscape mode, each app uses the original ROM code and provides an exact visual replica of the actual horizontal-format calculator, making it familiar to users of the originals. The $15 HP 12c and $20 HP 12c Platinum provide the same business-focused functions and formulas as the hardware models, and the $30 HP 15c includes all of the original’s scientific algorithms and calculation sequences, including matrix, root, and complex-number functions. All three apps are also, like their hardware counterparts, programmable.

Here’s the rundown again:

• HP 12C Financial Calculator [$14.99 - iTunes link]
• HP 12C Platinum Calculator [$19.99 - pending]
• HP 15C Scientific Calculator [$29.99 - iTunes link]

Anyone compelled to pick up one of those heavy crunchers, and if so, which one, what makes it compelling, and does it feel enough like the hardware version for you?