I'd like to put out an argument that no WWI might actually have a slowing effect on a lot of non-military technology. My reasoning is more that:
-On the one hand, most of the countries in Europe were pouring huge amounts of money into mass armies. Witness the size of the German, Austrian, etc. armies in 1914 in Nations at War (a wonderful, albeit somewhat slanted, reference book from 1918 which I grew up reading): In many cases, the government was at least paying to train and equip 5-10% of their population. That's a lot of money being spent on a staring contest, and there's no reason to suggest that the numbers wouldn't have increased on this front over time absent a war to break the staring contest.
-On the other hand, there's a good deal of forced industrialization and centralization that WWI triggered. Mind you, many of the European countries were pretty industrialized already, but a lot of things had to be scaled up...and with it, a certain amount of reorganization took place (witness the British railroad industry...WWI basically caused the consolidation into the "Big Four", and WWII was a major factor in the formation of British Rail) as a result. Most of this probably would have happened anyway, but I think the argument is there to be had that the war sped a lot of things up through this sort of consolidation (not to mention some resulting standardization) in many countries.
--A knock-on from this is that losing the "War Socialism" test from 1917-19 would probably restrict the US government's efforts to consolidate the airline industry. Again, a shakeout was likely, but you get a lot of cases where 30 years' progress gets packed down into 5 (and there's always the chance that an ICC-esque regime gets started early on and the US winds up with 35 regional airlines in the 1950s...now there's a thought!). The side-effects on investment in passenger aircraft, at the very least (and possibly cargo hauling aircraft) could be rather substantial if there aren't a handful of big airlines which you can hope to sell a lot of them to.