(Credit: Apple)

It's been clear for a while that Apple seems to have settled into mid-year iPhone refresh cycles as it closes in on the two-year anniversary of its debut, but more signs are pointing to a summer launch.

Think Equity Partners put out a report this week, spotted by AppleInsider, that says Apple has essentially cleaned out Samsung's supply of flash memory in recent weeks. Apple has also asked Toshiba and Hynix to step up with more flash memory, according to Think Equity, as it prepares for an iPhone launch.

Apple has a contract in place with the three companies, as well as Intel and Micron, to supply flash memory for Apple's products through 2010. But Apple tends to launch new iPods in the second half of the year around a September music event, making it much more likely that this build-up has a new iPhone in mind.

In January, Apple senior vice-president of worldwide marketing Phil Schiller hinted that Apple has settled on a mid-year refresh cycle for iPhones, after launching the original iPhone in late June and the iPhone 3G in July. The spring parade of iPhone rumours has not fully blossomed as of yet, but one persistent rumour is that Apple has some sort of low-cost iPhone in the pipeline, based on CEO Steve Jobs' comments about price umbrellas during an earnings conference call and a recent report suggesting a US$99 iPhone is on tap.

Apple COO Tim Cook, however, has dismissed talk of Apple playing in the entry-level phone business, so as usual, it's hard to tell exactly what Apple has in mind. But even if all Apple did was double the storage capacity of the iPhone to 16GB and 32GB, it would need a lot more flash memory chips.