Instapaper developer Marco Arment may have found evidence of the rumored iPad Mini, a smaller and cheaper version of Apple's market-leading tablet. Arment found signs indicating that two new iPad 2 models have been accessing his app, and the models may be the much-rumored new tablet.

The developer observed "two curious entries" in Instapaper's device stats on Thursday, Aug. 30. The two entries were an iPad 2.5 and an iPad 2.6, and Arment had never seen these device names before. The device numbers could be spoofed by jailbroken devices, but Arment believes they are in fact a Wi-Fi and GSM model of the iPad Mini.

"Who would fake an oddly numbered iPad 2?" the developer wrote on his blog. "A faker would almost certainly choose iPad 4.1."

Apple's iPad 2.1, iPad 2.2 and iPad 2.3 were the original Wi-Fi, GSM, and CDMA versions released in 2011. The iPad 2.4 is the cheaper 16GB Wi-Fi iPad 2 introduced earlier this year, with the launch of the third-generation iPad. The two new models Arment spotted could be the GSM and CDMA versions of the updated iPad 2, but with numerous reports hinting to a smaller iPad, "a more likely explanation" is that they are in fact the expected iPad Mini, wrote the developer.

During Apple's high-profile patent trial against Samsung, the South Korean company revealed an e-mail between Apple vice president Eddy Cue and his colleagues, saying that late Apple CEO Steve Jobs was open to creating a smaller version of the iPad. "I believe there will be a 7-inch market and we should do one," Cue wrote in his e-mail. "I expressed this to Steve several times since Thanksgiving and he seemed very receptive the last time."

The so-called iPad Mini, expected sometime in October, will reportedly function like an iPad, but will look more like an oversized iPod Touch. According to recent reports, the gadget will sport a 7.85-inch display with a 1024 x 768 resolution. Meanwhile, the iPad 2 naming in Instapaper's device logs indicate the smaller iPad will pack iPad 2 internals like an A5 processor and 512MB of memory.

Apple has not confirmed plans to launch a smaller version of the iPad.