Tech stocks are certainly not immune to the global downturn, but when Apple’s (Nasdaq:AAPL) sales decline the sector could be in for a dragged-out recession. Coupled with a surprisingly aggressive downturn in semiconductor sales for next year, it could be 2010-2011 before we see any significant opportunities for investors in anything digital.

Starting with PCs, U.S. retail sales of Apple of Apple’s desktop Macs slipped 1% last month over the previous year. At the same time, PCs sales increased 2%. The message on the wall here is that American consumers are going down-market for their computers – scooping up the commodity low-margin models that eat away at the corporate bottom line.

Given that Apple’s slowdown comes during the ramp-up for holiday sales, the projections for early 2009, and perhaps the entire year, are expected to look dismal for its Mac family of desktops.

It seems that during hard times, consumers are willing to forego Apple’s premium pricing strategy in favor of stripped-down models that still provide basic functionality.

The market slump for Macs hit fast and hard. It was only the previous month, October, which shipments had surged 28% from the year before. That dramatic reversal indicates a panic mentality among consumers, which could in fact take all of next year to overcome.

The shift in buying trends not only hurts the manufacturers but the retailers as well.

Yesterday, Best Buy Co. (NYSE:BBY) said it would reduce capital spending and offer buyouts to corporate employees. The electronics retailer posted a 77% drop in quarterly profit over the same period a year ago.

Slashing capital expenditures by 50% next year primarily means that the company would open fewer stores – further eroding revenue projections.

The news was even worse at competitor Circuit City Stores, which filed for bankruptcy last month.

Naturally, semiconductor companies which supply the components to all these products would be hit as well. Unfortunately, even these experts at market predictions got blind-sided by the sudden reversal.

Just as Apple’s Mac sales dropped some 29% in the period of a month, semiconductor revenues hit the skids much faster and longer than originally anticipated.

Worldwide chips sales are expected to decline 16% next year, resulting in the industry’s first-ever two-year sales slide, said research firm Gartner Inc.

The 16% pull back represents a higher revised number from Gartner, which had predicted a drop of 2.2% only last month.

Overall, 2009 is clearly not the year to dive into tech. Even value investing can be precarious right now with no relief in sight for more jobs, more credit and more demand. While this can be a frustrating period for tech investors, it’s much better to sit on the sidelines than stand in a bread line.