Amazon/Ebay pickup locations in Frankfurt/Munich/Vienna airport?

Both Germany and Austria have several competing package delivery companies, each with their own pick-up locations. First you've got to ensure you know which one(s) your seller uses.

In Germany, Amazon defaults to shipping by DHL / Deutsche Post but Amazon Marketplace and eBay sellers may use any shipping company.

• DHL / Deutsche Post (who also run traditional post offices) offer Packstations which are pretty impractical to use as a visitor since you need a membership card. They do offer Postfiliale Direkt: pick up at the post office which requires you to register at paket.de for a PostNumber and then allows you to have packages shipped to a participating post office using addressing instructions here. The location within Munich Airport does not offer this service, but there is a post office two stops down the S11 local train in Neufahrn (open 8a-8p weekdays and Saturday mornings) that does. The location in Frankfurt Airport terminal does offer this service (open 8a-7p weekdays, 11a-6p weekends).
• Hermes offers shipping to a local retail partner called Shop2Shop. Packages will be held there for a Maximum of 10 days. Locations include the Munich Airport OMV petrol station (open 24/7) and several locations around Frankfurt Airport including the Aral petrol station in Mörfelden (open 24/7).
• UPS allows you to order packages to their service centers with your name and "Für Abholung bereithalten" [Hold for pickup], they'll hold the package for up to 5 days. Near Munich Airport, they've got a Access Point at the Aral petrol station two stops down the S11 local train and a long walk in Neufahrn (open 5a-12a daily). There are locations scattered near Frankfurt Airport including at Mail Boxes Etc. in Kelsterbach (weekdays 10a-6p), one stop on the local train outside of the airport.
• GLS
• TNT
• Keavo

In Austria, there's a particular challenge to understand who'll deliver your order since many orders to Austria are shipped from Germany, and depending on the size it's often not clear if it will come via Post.at or DHL once it gets to Austria.

• Post.at (who also run the traditional post office and deliver most Deutsche Post letters from Germany - including small boxes - in Austria, as well as most all boxes sent from Austria) have very simple service for delivering to their post office branches. They don't seem to have a branch in the airport, but there's one one stop down the S7 local train line in Schwechat (open weekdays 8a-6p). Alternatively, the Vienna Central post office (9a-10p daily) is a couple blocks from the end of the Vienna Airport Lines Morzinplatz/Schwedenplatz route 20 minutes from the airport.
• DHL (who deliver most DHL Deutsche Post packages from Germany in Austria) have a horrible reputation for customer service and only one location in Vienna which is not particularly convenient to the airport. You have to order your package first using an address (I'd just use theirs) and then register your tracking number at delivernow.at and then give them a call.
• LogoiX or similar company on the border might be worth looking into: you order the package to their German address using your customer number and they bring it across the border and put it in Austrian domestic mail (Post.at) so you can be sure it'll end up at the post office in Austria (and not with DHL). I'm not sure they're willing to do this if you can't prove residency at an address though, and you may need a local payment method.
• Hermes
• UPS allows you to order packages to their service centers with your name and "Für Abholung bereithalten" [Hold for pickup], they'll hold the package for up to 5 days. They have an office at Vienna Airport's Cargo Area which a not very pleasant 15 minute walk from the passenger terminals or there may be a shuttle bus you can take.
• GLS

Sure, Packstation 802 is at the Munich airport, Level 3. However, if you are not a German resident under Receive packages from Amazon.de while in Germany for 3 weeks (Tourist) we discussed to death how unlikely you will have a Packstation chipcard for this.